If you are talking about the 3rd Generation iPod, then there is no lock on it other then the possibility of a screen lock. If you are talking about the 3rd Generation iPod touch, the max version of iOS it can run is 5.1.1 which predates the use of Activation Lock, which is the "lock" I assume you are talking about.
If you are talking about an iPod touch 5th Generation which is running iOS 7 or newer with Activation Lock enabled, the only way to get around it is to use Apple's iForgot website and reset the password for the Apple ID the iPod is tied too. If you don't know the Apple ID at all, there is nothing that can be done because not even Apple can unlock it.