SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cdb8c9078f5613d9179aac6196ee1003753b95fd078d99827e7ea1e25968d29' 
  AND token = '2irlHkO8FOAkbkHmpimkf6SmCJqNljqZ4WvMNrsIxc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}