I couldn’t find any documentation on the internet about this so here is how you can change the frequency of checking the scheduled task.
As you can see here in the config file you can do it separately for “core” and “master” database. On dev machines always needed to change it from the default 10 minutes to lower, e.g. 1 minute.
To do that you should change the “interval” attribute in Sitecore.Processing.config file on the “agent” nodes.