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 (
    93167, 93168, 93169, 93170, 93171, 93172, 
    93173, 93174, 93175, 93176, 93177, 
    93178, 93179, 93180, 93181, 93182, 
    93183, 93184, 93185, 93186, 93187, 
    93188, 93189, 93190, 93191, 93192, 
    93193, 93194, 93195, 93196
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00072

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 (93167,93168,93169,93170,93171,93172,93173,93174,93175,93176,93177,93178,93179,93180,93181,93182,93183,93184,93185,93186,93187,93188,93189,93190,93191,93192,93193,93194,93195,93196)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
93167
93168
93169
93170
93171
93172
93173
93174
93175
93176
93177
93178
93179
93180
93181
93182
93183
93184
93185
93186
93187
93188
93189
93190
93191
93192
93193
93194
93195
93196