In EJB 3.1 I can get all timers for a specific bean using TimerService#getTimers() on the TimerService instance obtained for that bean.
What I actually need however
EJB 3.2 has a method called "getAllTimers()".
https://docs.oracle.com/javaee/7/api/javax/ejb/TimerService.html#getAllTimers--
Description: Returns all active timers associated with the beans in the same module in which the caller bean is packaged. These include both the programmatically-created timers and the automatically-created timers.