I have an idea but there are some problems. The idea is
Try checking for people who use auto clickers, create a table and get the delta time of the current click and the previous click. Then wait for around 10 seconds (Stop waiting if player stopped clicking for 1 second), and calculate the results. If they have a very very precise delta time, like 0.15631, 0.15427, 0.15598 or something like that, then suspect them, and do something.
Now the problems is, first, if a person normally has a constant cps without auto clicker, they could get suspected. Second, if the exploiter is smart, they could create an A.I. or something that stops and continues the auto clicking at random times. Third, if the auto clicker is so bad that it can not get a constant speed, it wont get suspected. And I am not sure if this is a problem, but the performance might get affected by this.