SELECT 
  jmj_product_descriptions.product_id, 
  jmj_product_descriptions.short_description, 
  IF(
    jmj_product_descriptions.short_description = '' 
    OR jmj_product_descriptions.short_description IS NULL, 
    jmj_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  jmj_product_descriptions 
WHERE 
  jmj_product_descriptions.product_id IN (
    1701, 1708, 1726, 1694, 1693, 1712, 1715, 
    1716, 1718, 1724, 1722, 1736, 1706, 
    1710, 1698, 1585, 1591, 1612, 1583, 
    1568, 1596, 1599, 1600, 1603, 1609, 
    1605, 1586, 1589, 1594, 1584
  ) 
  AND jmj_product_descriptions.lang_code = 'en'

Query time 0.01106

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "72.01"
    },
    "table": {
      "table_name": "jmj_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "index_condition": "((`jmj_test`.`jmj_product_descriptions`.`product_id` in (1701,1708,1726,1694,1693,1712,1715,1716,1718,1724,1722,1736,1706,1710,1698,1585,1591,1612,1583,1568,1596,1599,1600,1603,1609,1605,1586,1589,1594,1584)) and (`jmj_test`.`jmj_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "66.01",
        "eval_cost": "6.00",
        "prefix_cost": "72.01",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}