SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description, 
  cscart_product_descriptions.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    12954, 12955, 12947, 12949, 12946, 12948, 
    12956, 17725, 17726, 17727, 17728, 
    17729, 17730, 17731, 17732, 12958, 
    12960, 12959, 12962, 12964
  ) 
  AND cscart_product_descriptions.lang_code = 'kk'

Query time 0.00148

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 20,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (12954,12955,12947,12949,12946,12948,12956,17725,17726,17727,17728,17729,17730,17731,17732,12958,12960,12959,12962,12964) and cscart_product_descriptions.lang_code = 'kk'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
12946
12947
12948
12949
12954
12955
12956
12958
12959
12960
12962
12964
17725
17726
17727
17728
17729
17730
17731
17732