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 (
    1501, 1487, 1498, 1497, 1496, 1491, 1495, 
    1493, 1486, 1489, 1488, 1485, 1459, 
    1477, 1484, 1483, 1482, 1480, 1481, 
    1474, 1479, 1478, 1465, 1475, 1476, 
    1473, 1276, 1463, 1471, 1462, 1267, 
    1460, 820, 1472, 1464, 1470, 1469, 1468, 
    1467, 1466, 1461, 1458, 1457, 1456, 
    1455, 1454, 1446, 1450
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00149

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 (1501,1487,1498,1497,1496,1491,1495,1493,1486,1489,1488,1485,1459,1477,1484,1483,1482,1480,1481,1474,1479,1478,1465,1475,1476,1473,1276,1463,1471,1462,1267,1460,820,1472,1464,1470,1469,1468,1467,1466,1461,1458,1457,1456,1455,1454,1446,1450) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
820
1267
1276
1446
1450
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1491
1493
1495
1496
1497
1498
1501