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 (
    95759, 95773, 95777, 95827, 95828, 97609, 
    97616, 97634, 97698, 97703, 99113, 
    99117, 99131, 99135, 99144, 99165, 
    99168, 99174, 99176, 99179, 99193, 
    99198, 99199, 99208, 99219, 99233, 
    99249, 99250, 99254, 99256
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00089

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 (95759,95773,95777,95827,95828,97609,97616,97634,97698,97703,99113,99117,99131,99135,99144,99165,99168,99174,99176,99179,99193,99198,99199,99208,99219,99233,99249,99250,99254,99256)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}