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 (
    1735, 1602, 1601, 1692, 1696, 1682, 1743, 
    1045, 1046, 1187, 1556, 1555, 1435, 
    1554, 1577, 1194, 1766, 368, 1253, 1553, 
    1371, 1372, 1373, 1374, 1219, 1220, 
    1440, 1441, 1681, 1680, 1800, 1902, 
    1804, 1803, 1221, 1224, 1762, 408, 39, 
    1798, 1797, 1445
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00146

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": 42,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (1735,1602,1601,1692,1696,1682,1743,1045,1046,1187,1556,1555,1435,1554,1577,1194,1766,368,1253,1553,1371,1372,1373,1374,1219,1220,1440,1441,1681,1680,1800,1902,1804,1803,1221,1224,1762,408,39,1798,1797,1445) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
39
368
408
1045
1046
1187
1194
1219
1220
1221
1224
1253
1371
1372
1373
1374
1435
1440
1441
1445
1553
1554
1555
1556
1577
1601
1602
1680
1681
1682
1692
1696
1735
1743
1762
1766
1797
1798
1800
1803
1804
1902