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.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    6114, 5647, 6146, 6187, 5651, 6086, 6299, 
    6307, 5508, 6081, 6144, 6254, 6228, 
    6192, 6227, 6083, 6230, 6275, 6258, 
    6255, 6229, 6256, 6189, 6257, 6259, 
    6145, 5644, 6226, 6297, 6190, 6276, 
    6303, 6260, 6305, 6274, 6301, 10074, 
    10088, 10157, 6822
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00174

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.33"
    },
    "table": {
      "table_name": "cscart_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": 40,
      "rows_produced_per_join": 40,
      "filtered": "100.00",
      "index_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`product_id` in (6114,5647,6146,6187,5651,6086,6299,6307,5508,6081,6144,6254,6228,6192,6227,6083,6230,6275,6258,6255,6229,6256,6189,6257,6259,6145,5644,6226,6297,6190,6276,6303,6260,6305,6274,6301,10074,10088,10157,6822)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "24.33",
        "eval_cost": "4.00",
        "prefix_cost": "28.33",
        "data_read_per_join": "182K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}