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 (
    417, 433, 580, 514, 471, 654, 263, 1037, 
    574, 495, 813, 1086, 844, 756, 755, 434, 
    863, 220, 823, 610, 867, 858, 635, 1044, 
    579, 578, 1127, 1042, 868, 517, 938, 
    946, 456, 559, 542, 407, 866, 515, 561, 
    491, 493, 573, 651, 562, 435, 523, 650, 
    583
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00178

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 (417,433,580,514,471,654,263,1037,574,495,813,1086,844,756,755,434,863,220,823,610,867,858,635,1044,579,578,1127,1042,868,517,938,946,456,559,542,407,866,515,561,491,493,573,651,562,435,523,650,583) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
220
263
407
417
433
434
435
456
471
491
493
495
514
515
517
523
542
559
561
562
573
574
578
579
580
583
610
635
650
651
654
755
756
813
823
844
858
863
866
867
868
938
946
1037
1042
1044
1086
1127