Recently, I installed a new local MySQL Server with the purpose to log debug messages.
But because I had to log a lot of messages disk space became an issue. So I decided to create an event to clear these messages hourly.
I spent a lot of time trying to understand why the code worked fine in a single execution, but when the same code was inside the event it was not working when the schedule was met.
After some reasearch I found out that by default event_scheduler global variable is OFF.
After enabling it, the event started to work.
You just need to execute the line:
SET GLOBAL event_scheduler = ON;