I was in the timber business for 15 years. I removed countless Master locks with a pair of channel lock pliers and a hammer.

1. Grab lock with channel locks and apply downward pressure;

2. Tap on the side of the lock with the hammer.

When you tap it with the hammer it causes the spring loaded tumblers to bounce back in the open position, but only for a fraction of a second.
The downward pressure with the channel locks causes the lock to immediately open.