640 is "probably" good enough to get you into USC's PM program. UCLA's average GMAT is 690-700 so you'd have some work ahead of you.
Since you have 1 year of experience under your belt, I'd recommend working another year and, while doing so, studying up on the verbal portion. With practice and a bit of time, you'll be able to increase your verbal score significantly.
Once you get your verbal to 38+, you'll be in 700 land (assuming your math stays where it is), and you'll have more options at your fingertips.
Who knows, after 2 years of work, you might want to go full time. If that's the case, you'll want to get a 730+ to take the GMAT hurdle out of the way.