I inadvertently locked my HTC 1 via "find my phone" (wrong phone). I "found" it but cannot access it.
This should be the screen you should see on your phone when you remotely lock it using Google's 'find my device' 

Simply drag the lock icon in any direction and that will direct you to a page where you can enter the code that you have set when remotely locking the device. On newer devices, it will ask you to enter the regular code that you use when unlocking your phone.

If the above is not what you see on your screen, then restarting your phone should bring it up.