Cafe Boogaloo in Hermosa Beach has a pretty good happy hour every day from 2-8pm I think. They *may* have changed it since the last time I was there, but they had $5 pints of Pliny during happy hour. Even if the Pliny isn't available they still have Racer 5 and some other good taps that rotate. Also they have cheap eats, and I think on Tuesdays they have a good deal on tacos, which I always seem to miss but my friends keep talking about.
It might actually start earlier like 1pm, although that probably doesn't matter to you.