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 (
    3112, 3944, 3664, 3126, 2230, 2655, 3741, 
    5683, 3440, 5890, 2226, 5859, 3843, 
    3840, 3130, 3441, 3811, 6054, 2221, 
    5891, 3153, 3924, 3377, 2522, 2719, 
    6041, 5111, 3385, 5948, 8240, 3551, 
    3831, 5927, 3289, 10078, 3382, 3519, 
    3356, 6093, 6194
  ) 
  AND cscart_product_descriptions.lang_code = 'ar'

Query time 0.00149

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 (3112,3944,3664,3126,2230,2655,3741,5683,3440,5890,2226,5859,3843,3840,3130,3441,3811,6054,2221,5891,3153,3924,3377,2522,2719,6041,5111,3385,5948,8240,3551,3831,5927,3289,10078,3382,3519,3356,6093,6194)) 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"
      ]
    }
  }
}