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 (
    82963, 83336, 83337, 83346, 83347, 86488, 
    86764, 83548, 85078, 85164, 85210, 
    85256, 86623, 86692, 82597, 82598, 
    83037, 83045, 83360, 83361, 83594, 
    90873, 90881, 90952, 90960, 82621, 
    83424, 85118, 82627, 83492, 83258, 
    83265, 86496, 86657, 86726, 86772, 
    85310, 85407, 85458, 85509, 86635, 
    86636, 86704, 86705, 85356, 82815, 
    82888, 82961
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00059

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 (82963,83336,83337,83346,83347,86488,86764,83548,85078,85164,85210,85256,86623,86692,82597,82598,83037,83045,83360,83361,83594,90873,90881,90952,90960,82621,83424,85118,82627,83492,83258,83265,86496,86657,86726,86772,85310,85407,85458,85509,86635,86636,86704,86705,85356,82815,82888,82961)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}