Even if you basment is dry there will still be moisture in the florr area do to the differnce in temperature.
I just did my basement floor. Underneath the OSB i put a product called Delta FL. It's a plastic membrane that provide an airgap between tth floor and the plywood. It is about 3/8 thick so you don't lose much head room. It was easy to install and feels great so far. I am so glad i did it