I don't think this is a fold. It's such a dry board that any strong hand would more than likely go for a check/raise rather than a donk bet. It could be complete air, a draw or middle pair (More unlikely in my opinion).
A likely range for him could be something like: AJ, AQ, AT, JT, QT, QJ and then a load of small/mid pocket pairs that just bet hoping to take it down.
So it depends which part of his range you give more weight to here, his draws or his air/marginal hands. If it's his draws, raise here for value and to protect. If it's his marginal holdings, you can call and let him keep betting into you.
If you do decide to raise the flop though you will have to fold to a 3bet from him.