"One person stated that I should clean out the WD-40 the best I could and use graphite in my locks. "
This is the best advice. Not that WD40 isn’t OK short term, but graphite, a dry lube works best. WD40 will attract dirt and gum up over time if the solvent evaporates quickly in heated areas later. it’s a petro product. You would not put oil in the lock for the same reason as over time it could cause problems. Initially it seems to do the trick, but not a long term solution. Ask a lock smith. Use a deicing compound that evaporates then apply graphite to the key and work it into the lock. I do believe that a combination of wd40 and graphite could be the worse as VDC alluded to.