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 (
    1584, 1564, 1583, 5939, 5918, 3935, 5961, 
    1566, 5925, 3938, 1580, 2277, 3930, 
    2283, 2281, 1581, 1582, 2279, 2284, 
    2280, 3955, 2282, 2285, 3931, 3960, 
    3954, 3934, 3961, 4006, 3958, 3933, 
    4005, 3962, 3963, 5249, 3957, 4002, 
    5198, 5915, 5960
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00137

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 (1584,1564,1583,5939,5918,3935,5961,1566,5925,3938,1580,2277,3930,2283,2281,1581,1582,2279,2284,2280,3955,2282,2285,3931,3960,3954,3934,3961,4006,3958,3933,4005,3962,3963,5249,3957,4002,5198,5915,5960)) 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"
      ]
    }
  }
}