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 (
    97197, 97198, 97199, 97200, 97201, 97202, 
    97203, 97204, 97205, 97206, 97207, 
    97208, 97209, 97210, 97211, 97212, 
    97213, 97214, 97215, 97216, 97217, 
    97218, 97228, 97229, 97230, 97231, 
    97232, 97233, 97234, 97235
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00088

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 (97197,97198,97199,97200,97201,97202,97203,97204,97205,97206,97207,97208,97209,97210,97211,97212,97213,97214,97215,97216,97217,97218,97228,97229,97230,97231,97232,97233,97234,97235)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97197
97198
97199
97200
97201
97202
97203
97204
97205
97206
97207
97208
97209
97210
97211
97212
97213
97214
97215
97216
97217
97218
97228
97229
97230
97231
97232
97233
97234
97235