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 (
    532, 623, 509, 897, 361, 512, 746, 740, 
    984, 707, 317, 745, 529, 834, 380, 1278, 
    436, 586, 596, 1075, 450, 743, 741, 449, 
    747, 1053, 415, 45, 1074, 1240, 431, 
    1244, 1050, 1052, 1089, 939, 889, 1107, 
    620, 379, 903, 316, 594, 533, 812, 430, 
    451, 614
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00152

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": 48,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (532,623,509,897,361,512,746,740,984,707,317,745,529,834,380,1278,436,586,596,1075,450,743,741,449,747,1053,415,45,1074,1240,431,1244,1050,1052,1089,939,889,1107,620,379,903,316,594,533,812,430,451,614) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
45
316
317
361
379
380
415
430
431
436
449
450
451
509
512
529
532
533
586
594
596
614
620
623
707
740
741
743
745
746
747
812
834
889
897
903
939
984
1050
1052
1053
1074
1075
1089
1107
1240
1244
1278