MySQL: how to insert only if update fails

There is a [similar question](https://stackoverflow.com/questions/52283031/running-a-mysql-insert-when-update-fails) , but my requirement is **different**. The table schema is:

CREATE TABLE device (
  id int NOT NULL,
  device_type varchar(64) NOT NULL,
  serial varchar(128) NOT NULL,
  revoked bigint NOT NULL DEFAULT '0',
  created datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  updated datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (id,serial,revoked)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb3 COLLATE=utf8_unicode_ci

I want to insert into the table with a pair of (id, serial), if **neither** of id or serial appears in the table. So, I think I might do this:

UPDATE device SET updated='' WHERE id='' OR 
serial='' ON UPDATE FAIL INSERT (id,serial,...) VALUES (...)

The **ON UPDATE FAIL...** part is hypothetical. I know that MySQL does not have this syntax. So I want a **transactional** way to accomplish this. Note that the PRIMARY KEY cannot be modified, although adding other indexes is allowed, without change business logic, of course.