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 (
    84899, 86486, 86487, 86762, 86763, 84314, 
    88875, 88876, 88877, 88878, 88902, 
    88903, 82798, 82871, 82944, 83253, 
    83260, 84798, 84799, 86601, 86602, 
    86670, 86671, 91068, 85071, 85157, 
    85203, 85249, 82619, 82620, 83422, 
    83423, 89762, 83029, 83227, 83232, 
    83586, 84668, 84669, 84878, 90865, 
    90944, 85093, 85179, 85225, 85271, 
    82580, 82581
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00141

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "26.87"
    },
    "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": "22.07",
        "eval_cost": "4.80",
        "prefix_cost": "26.87",
        "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 (84899,86486,86487,86762,86763,84314,88875,88876,88877,88878,88902,88903,82798,82871,82944,83253,83260,84798,84799,86601,86602,86670,86671,91068,85071,85157,85203,85249,82619,82620,83422,83423,89762,83029,83227,83232,83586,84668,84669,84878,90865,90944,85093,85179,85225,85271,82580,82581)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}