Having a pet is both the least frustrating way to get keys and the most irritating to others.
Spawn a pet (or, if you're a non-pet class, grab a dragon tooth that spawns a pet for you)
Make a bind like this:
/target a_barrel
/pet attack
Go to the room with the 3 (or is it 4?) barrels, stand next to the locked chest and spam away the bind. The /target command will even highlight barrels not in your line of sight, and the pet will go through walls to attack them.
There are 6 or 7 different barrels that you'll be able to target and zero chance of being caught and sent back to the nexus. The best part is that you don't have to "save up" keys or anything like that since you can continuously try each one against the locked chest you're standing next to.
You get decent barrel-breaking-per-minute, and is foolproof and brainless: once you're in your spot, you can just spam-click the mouse or hotkey; no turning, no manual targeting, no need for quick reaction time. You don't even need to be looking at the screen, you can just keep clicking or pressing while watching a movie
...which leads me to wonder, are there "camping" rules in the hushed banquet, or can you do something like this and own a fair portion of the zone?