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 (
    93495, 93496, 93497, 93498, 93499, 93500, 
    93501, 93502, 93503, 93504, 93505, 
    93506, 93507, 93508, 93509, 93510, 
    93511, 93512, 93513, 93514, 93529, 
    93530, 93531, 93532, 93533, 93534, 
    93535, 93536, 93537, 93538
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (93495,93496,93497,93498,93499,93500,93501,93502,93503,93504,93505,93506,93507,93508,93509,93510,93511,93512,93513,93514,93529,93530,93531,93532,93533,93534,93535,93536,93537,93538)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}