SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  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') 
WHERE 
  cscart_products_categories.product_id IN (
    17792, 17791, 17790, 17789, 17788, 17787, 
    17786, 17785, 17784, 17775, 17774, 
    17773, 17772, 17753, 17752, 17751, 
    17750, 17749, 17748, 17747, 17746, 
    17745, 17744, 17743, 17742, 17783, 
    17782, 17781, 17780, 17779, 17778, 
    17777, 17776, 17741, 17740, 17739, 
    17738, 17737, 17771, 17770, 17769, 
    17768, 17767, 17766, 17765, 17764, 
    17763, 17762, 17761, 17760, 17759, 
    17758, 17757, 17756, 17755, 17754, 
    17736, 17735, 17734, 17733, 17730, 
    17732, 17731, 17729, 17728, 17727, 
    17726, 17725, 17667, 17679, 17678, 
    17677, 17676, 17675, 17674, 17673, 
    17672, 17671, 17670, 17669
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00082

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products_categories",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "pt"],
      "key": "pt",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 141,
      "filtered": 100,
      "index_condition": "cscart_products_categories.product_id in (17792,17791,17790,17789,17788,17787,17786,17785,17784,17775,17774,17773,17772,17753,17752,17751,17750,17749,17748,17747,17746,17745,17744,17743,17742,17783,17782,17781,17780,17779,17778,17777,17776,17741,17740,17739,17738,17737,17771,17770,17769,17768,17767,17766,17765,17764,17763,17762,17761,17760,17759,17758,17757,17756,17755,17754,17736,17735,17734,17733,17730,17732,17731,17729,17728,17727,17726,17725,17667,17679,17678,17677,17676,17675,17674,17673,17672,17671,17670,17669)"
    },
    "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.cscart_products_categories.category_id"],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "cscart_categories.storefront_id in (0,1) 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')"
    }
  }
}