Just like the Well, the Player won't always need to check this since the 1.5 Update as there are two escape procedures.
Despite it making a noticeably loud sound, opening the safe does not alert Granny, although dropping the Safe Key does.
Originally, on preset #4, the Player could reach the Cutting Pliers from inside the Safe without having to use the Safe Key. On the right side of the safe, there is a gap where you can reach for them and grab it. However, this was patched in Version 1.3.2. In 1.4, you could also do the same thing on the bottom left edge of the Car Trunk and grab the Hammer on preset #3, but this was patched in Version 1.5.