Babis answers that it wasn't the vaults. He isn't crazy enough to break into that! He was only trying to have some fun, not get himself jailed forever. He said it one of the wine merchant's cellar at a fancy party he was invited to as a plus one.

He answers he hasn't been in Ikorr long enough to study the vaults below, but Ikorr looks like it heavily relies on magical wards. With that in mind, the biggest challenge would be the magic. Once that's broken, the physical locks would likely be child's play.