The demo shop will show you if a redirect is linked to a search query. Open up the demo shop and type a search query. Below the search algorithm at the bottom of the page, you'll see the redirect if it's been set up correctly.
Having other issues with your redirects?
A redirect is triggered, but I don't see it in Tweakwise. How come?
I can't see a search term in Google Analytics after I've set a redirect. How do I solve this?