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 (
    4570, 1615, 2228, 2593, 3743, 4567, 3112, 
    2441, 2877, 2938, 3944, 4598, 4752, 
    5250, 7616, 5919, 3569, 5817, 3033, 
    5923, 4503, 3104, 4138, 2177, 2942, 
    3664, 5936, 3126, 3370, 7293, 2203, 
    2618, 2788, 4225, 5837, 7279, 7617, 
    2649, 7620, 855
  ) 
  AND cscart_product_descriptions.lang_code = 'ar'

Query time 0.00154

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 (4570,1615,2228,2593,3743,4567,3112,2441,2877,2938,3944,4598,4752,5250,7616,5919,3569,5817,3033,5923,4503,3104,4138,2177,2942,3664,5936,3126,3370,7293,2203,2618,2788,4225,5837,7279,7617,2649,7620,855)) 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"
      ]
    }
  }
}