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 (
    170, 162, 168, 61, 166, 736, 734, 732, 
    733, 735, 737, 1569, 258, 257, 1783, 
    1779, 1782, 1781, 1676, 1229, 1181, 
    362, 256, 452, 420, 374, 800, 1136, 224, 
    795, 1839, 797, 798, 1409, 367, 1393, 
    484, 445, 157, 388, 585, 241, 629, 590, 
    860, 1790, 230, 413
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00164

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 (170,162,168,61,166,736,734,732,733,735,737,1569,258,257,1783,1779,1782,1781,1676,1229,1181,362,256,452,420,374,800,1136,224,795,1839,797,798,1409,367,1393,484,445,157,388,585,241,629,590,860,1790,230,413) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
61
157
162
166
168
170
224
230
241
256
257
258
362
367
374
388
413
420
445
452
484
585
590
629
732
733
734
735
736
737
795
797
798
800
860
1136
1181
1229
1393
1409
1569
1676
1779
1781
1782
1783
1790
1839