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 (
    2698, 3090, 3605, 2310, 3155, 2737, 2559, 
    2822, 2431, 2924, 3136, 1626, 2862, 
    2922, 2336, 3603, 2693, 3928, 2333, 
    2809, 2335, 2927, 1600, 3131, 2702, 
    3147, 3140, 1609, 3146, 3148, 3142, 
    3096, 2805, 3149, 3157, 3150, 3109, 
    2481, 3115, 3123
  ) 
  AND cscart_product_descriptions.lang_code = 'ar'

Query time 0.00244

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 (2698,3090,3605,2310,3155,2737,2559,2822,2431,2924,3136,1626,2862,2922,2336,3603,2693,3928,2333,2809,2335,2927,1600,3131,2702,3147,3140,1609,3146,3148,3142,3096,2805,3149,3157,3150,3109,2481,3115,3123)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'ar'))",
      "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"
      ]
    }
  }
}