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 (
    98542, 98543, 98544, 98545, 98546, 98547, 
    98548, 98549, 98557, 98558, 98559, 
    98563, 98564, 98565, 98566, 98567, 
    98568, 98569, 98690, 98693, 98694, 
    98758, 98759, 98762, 98769, 98770, 
    98771, 98772, 98773, 98774, 98775, 
    98776, 98777, 98778, 98779, 98780, 
    98781, 98782, 98783, 98784, 98785, 
    98786, 98787, 98788, 98789, 98790, 
    98791, 98792
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00103

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "25.94"
    },
    "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": "21.14",
        "eval_cost": "4.80",
        "prefix_cost": "25.94",
        "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 (98542,98543,98544,98545,98546,98547,98548,98549,98557,98558,98559,98563,98564,98565,98566,98567,98568,98569,98690,98693,98694,98758,98759,98762,98769,98770,98771,98772,98773,98774,98775,98776,98777,98778,98779,98780,98781,98782,98783,98784,98785,98786,98787,98788,98789,98790,98791,98792)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}