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 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    82430, 82431, 82433, 82558, 87387, 87389, 
    85575, 85579, 82372, 86889, 86895, 
    82359, 87383, 87384, 87385, 89612, 
    89613, 91896, 87888, 91844, 88932, 
    92185, 92382, 85561, 88393, 91856, 
    82407, 82427, 87386, 82429, 85591, 
    85597, 85600, 88910, 90755, 82350, 
    86343, 88909, 82368, 82370, 82376, 
    86893, 85553, 85556, 85557, 85559, 
    85589, 85593
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00049

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (82430,82431,82433,82558,87387,87389,85575,85579,82372,86889,86895,82359,87383,87384,87385,89612,89613,91896,87888,91844,88932,92185,92382,85561,88393,91856,82407,82427,87386,82429,85591,85597,85600,88910,90755,82350,86343,88909,82368,82370,82376,86893,85553,85556,85557,85559,85589,85593)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}