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 (
    498, 475, 496, 1091, 363, 483, 1072, 1071, 
    1085, 1076, 617, 1043, 887, 477, 634, 
    411, 478, 885, 518, 848, 904, 865, 626, 
    602, 601, 600, 605, 1133, 571, 637
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00122

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": 30,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (498,475,496,1091,363,483,1072,1071,1085,1076,617,1043,887,477,634,411,478,885,518,848,904,865,626,602,601,600,605,1133,571,637) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
363
411
475
477
478
483
496
498
518
571
600
601
602
605
617
626
634
637
848
865
885
887
904
1043
1071
1072
1076
1085
1091
1133