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 (
    2603, 3136, 2587, 2761, 2694, 3096, 2723, 
    2742, 3556, 2593, 3104, 2618, 2828, 
    2613, 2619, 2872, 2704, 3593, 4888, 
    3423, 5168, 2739, 3291, 5998, 2841, 
    5155, 3876, 2561, 3812, 5124, 6007, 
    2865, 2734, 3369, 6005, 6019, 3139, 
    5157, 2700, 5121, 5929, 2701, 6013, 
    2797, 6271, 5938, 5980, 4886, 4885, 
    8243, 5933, 6006, 5981, 6024, 5983, 
    8603, 10022, 8272, 7878, 8879, 7880, 
    8458
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00213

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.90"
    },
    "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": 62,
      "rows_produced_per_join": 62,
      "filtered": "100.00",
      "index_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`product_id` in (2603,3136,2587,2761,2694,3096,2723,2742,3556,2593,3104,2618,2828,2613,2619,2872,2704,3593,4888,3423,5168,2739,3291,5998,2841,5155,3876,2561,3812,5124,6007,2865,2734,3369,6005,6019,3139,5157,2700,5121,5929,2701,6013,2797,6271,5938,5980,4886,4885,8243,5933,6006,5981,6024,5983,8603,10022,8272,7878,8879,7880,8458)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "37.70",
        "eval_cost": "6.20",
        "prefix_cost": "43.90",
        "data_read_per_join": "282K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}