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 (
    4013, 4067, 4219, 4215, 4170, 4172, 4166, 
    4482, 4085, 4198, 4173, 4869, 4222, 
    4483, 4217, 4480, 4174, 4872, 4878, 
    3988, 4084, 4481, 4474, 4089, 4866, 
    4877, 4871, 4875, 4083, 4168, 4201, 
    4162, 4868, 4477, 4223, 4090, 4860, 
    4078, 4202, 4547, 4216, 4221, 4876, 
    4011, 4545, 4171, 4551, 4169, 4175, 
    4220, 4858, 4859, 4199, 4484, 4550, 
    4873, 4546, 4549, 4874, 4867, 4082, 
    4479, 4865, 4200, 4864, 4214, 4863
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00126

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "47.44"
    },
    "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": 67,
      "rows_produced_per_join": 67,
      "filtered": "100.00",
      "index_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`product_id` in (4013,4067,4219,4215,4170,4172,4166,4482,4085,4198,4173,4869,4222,4483,4217,4480,4174,4872,4878,3988,4084,4481,4474,4089,4866,4877,4871,4875,4083,4168,4201,4162,4868,4477,4223,4090,4860,4078,4202,4547,4216,4221,4876,4011,4545,4171,4551,4169,4175,4220,4858,4859,4199,4484,4550,4873,4546,4549,4874,4867,4082,4479,4865,4200,4864,4214,4863)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "40.74",
        "eval_cost": "6.70",
        "prefix_cost": "47.44",
        "data_read_per_join": "305K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}