There are a few rides (Dragon Challenge, Hulk, RRR) in which require you to put all your belongings into a locker (not just your bag) and you even go through a metal detector to make sure this happens, but as GaryDis said, they are free in the time they give you, which includes wait time and a little extra time to compensate for walking back and waiting to get to your locker.
Also, I do not know how possible this is, as all the rides are spread out, but honestly, I would recommend trying to get to the rides that require lockers first. Or if there are particular rides you want to focus on, go to the one who has lockers first in the park you're in. As in the morning it can be light with the crowds, but as the day goes on, a lot more people try to get lockers and while you can eventually get to one, I personally feel as if it's too claustrophobic and chaotic to me.