Middle pair in the BB

[fabadam]

I was wondering how to play this type of hand, it comes up quite often. Example:

First hand at the table, so no reads.
Hero has 97o in the BB. EP limps, button limps, SB completes, hero checks.

Flop comes K75r, SB checks, Hero ?

What's the best plan here? What kind of reads would make you change this generic plan?