Is it faster to work with array or with dict?

I have ~1Kb dict looking like:

db = {"word": 0, "something": 1, "another": 2, ..., "last": 36000}

and I use the following operations:

1. find an index of some word (like db["something"]);
2. find word by its index (like Object.keys($db)[1234])

It works slowly. Would it help if I switch to array?