There are images of the Stanwick St John registers at FindMyPast, but their T&Cs don't allow us to do look-ups, and as far as I can remember, this is incorporated in RootsChat's T&Cs. If you don't have a subscription you may be able to access FindMyPast at a public library.
If you're thinking of taking out a subscription to FindMyPast or some other site, bear in mind that some counties are mainly covered by one and others by another, so you'll have to decide which one's coverage best meets your needs.