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 (
    83883, 91764, 91580, 91581, 91582, 91583, 
    91584, 91585, 91586, 91587, 91588, 
    91589, 83877, 83880, 83889, 83890, 
    83893, 83895, 83884, 83886, 91627, 
    83891, 83892, 83896, 91700, 91701, 
    91702, 91703, 91704, 91705, 91706, 
    91707, 91571, 91572, 91573, 91574, 
    91575, 91576, 91577, 91578, 91579, 
    91610, 91611, 91612, 91613, 91614, 
    91615, 91616
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00151

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 (83883,91764,91580,91581,91582,91583,91584,91585,91586,91587,91588,91589,83877,83880,83889,83890,83893,83895,83884,83886,91627,83891,83892,83896,91700,91701,91702,91703,91704,91705,91706,91707,91571,91572,91573,91574,91575,91576,91577,91578,91579,91610,91611,91612,91613,91614,91615,91616)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}