SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  companies.company as company_name, 
  products.product_type, 
  products.parent_product_id 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'ru' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  LEFT JOIN cscart_companies AS companies ON companies.company_id = products.company_id 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  AND cscart_categories.storefront_id IN (0, 1) 
  LEFT JOIN cscart_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'ru' 
WHERE 
  1 
  AND companies.status IN ('A') 
  AND (
    products.amount > 0 
    OR products.tracking = 'D'
  ) 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
  AND products.parent_product_id = 0 
GROUP BY 
  products.product_id 
ORDER BY 
  (
    products.product_id NOT IN (
      12544, 12545, 12546, 12547, 12548, 12549, 
      12550, 12552, 12554, 12555, 12556, 
      12557, 12558, 12559, 12560, 12561, 
      12563, 12564, 12565, 12566, 12567, 
      12568, 12569, 12570, 12571, 12572, 
      12573, 12574, 12575, 12576, 12577, 
      12578, 12579, 12580, 12581, 12582, 
      12583, 12584, 12585, 12586, 12587, 
      12588, 12589, 12590, 12591, 12592, 
      12593, 12594, 12595, 12597, 12599, 
      12601, 12604, 12605, 12606, 12608, 
      12610, 12618, 12621, 12622, 12623, 
      12624, 12625, 12626, 12630, 12631, 
      12632, 12633, 12634, 12635, 12636, 
      12637, 12638, 12639, 12640, 12641, 
      12642, 12643, 12644, 12645, 12646, 
      12652, 12654, 12656, 13091
    )
  ) desc, 
  products.timestamp desc, 
  products.product_id ASC 
LIMIT 
  976, 16

Query time 0.02666

JSON explain

{
  "query_block": {
    "select_id": 1,
    "filesort": {
      "sort_key": "products.product_id not in (12544,12545,12546,12547,12548,12549,12550,12552,12554,12555,12556,12557,12558,12559,12560,12561,12563,12564,12565,12566,12567,12568,12569,12570,12571,12572,12573,12574,12575,12576,12577,12578,12579,12580,12581,12582,12583,12584,12585,12586,12587,12588,12589,12590,12591,12592,12593,12594,12595,12597,12599,12601,12604,12605,12606,12608,12610,12618,12621,12622,12623,12624,12625,12626,12630,12631,12632,12633,12634,12635,12636,12637,12638,12639,12640,12641,12642,12643,12644,12645,12646,12652,12654,12656,13091) desc, products.`timestamp` desc, products.product_id",
      "temporary_table": {
        "table": {
          "table_name": "companies",
          "access_type": "system",
          "possible_keys": ["PRIMARY"],
          "rows": 1,
          "filtered": 100
        },
        "table": {
          "table_name": "shared_descr",
          "access_type": "system",
          "possible_keys": ["PRIMARY", "product_id", "company_id"],
          "rows": 0,
          "filtered": 0,
          "const_row_not_found": true
        },
        "table": {
          "table_name": "prices",
          "access_type": "index",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "key": "usergroup",
          "key_length": "9",
          "used_key_parts": ["product_id", "usergroup_id", "lower_limit"],
          "rows": 1816,
          "filtered": 99.94493103,
          "attached_condition": "prices.lower_limit = 1 and prices.usergroup_id in (0,0,1)",
          "using_index": true
        },
        "table": {
          "table_name": "products",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "status", "idx_parent_product_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["noframes_angrybeaver.prices.product_id"],
          "rows": 1,
          "filtered": 93.45071411,
          "attached_condition": "products.parent_product_id = 0 and products.company_id = 1 and (products.amount > 0 or products.tracking = 'D') and (products.usergroup_ids = '' or find_in_set(0,products.usergroup_ids) or find_in_set(1,products.usergroup_ids)) and products.`status` = 'A'"
        },
        "table": {
          "table_name": "products_categories",
          "access_type": "ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "pt",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "ref": ["noframes_angrybeaver.prices.product_id"],
          "rows": 1,
          "filtered": 100
        },
        "table": {
          "table_name": "cscart_categories",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["category_id"],
          "ref": ["noframes_angrybeaver.products_categories.category_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "(cscart_categories.usergroup_ids = '' or find_in_set(0,cscart_categories.usergroup_ids) or find_in_set(1,cscart_categories.usergroup_ids)) and cscart_categories.`status` in ('A','H') and cscart_categories.storefront_id in (0,1)"
        },
        "table": {
          "table_name": "descr1",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "product_id"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["product_id", "lang_code"],
          "ref": ["noframes_angrybeaver.prices.product_id", "const"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "trigcond(descr1.lang_code = 'ru')"
        }
      }
    }
  }
}