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 (
    1705, 1713, 1702, 1719, 1723, 1696, 1699, 
    1707, 1697, 1735, 1695, 1686, 1721, 
    1636, 1627, 1638, 1640, 1618, 1621, 
    1632, 1620, 1624, 1616, 1613, 1639
  ) 
  AND jmj_product_descriptions.lang_code = 'en'

Query time 0.01093

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "60.01"
    },
    "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": 25,
      "rows_produced_per_join": 25,
      "filtered": "100.00",
      "index_condition": "((`jmj_test`.`jmj_product_descriptions`.`product_id` in (1705,1713,1702,1719,1723,1696,1699,1707,1697,1735,1695,1686,1721,1636,1627,1638,1640,1618,1621,1632,1620,1624,1616,1613,1639)) and (`jmj_test`.`jmj_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "55.01",
        "eval_cost": "5.00",
        "prefix_cost": "60.01",
        "data_read_per_join": "95K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}