To Cancel your subscription just login to your Paypal account and go to the Pre-approved payments section. You can find that here:

If you ordered directly with Paypal you should see the subscription listed and cancel it. This will cancel your Keysearch subscription at the end of the billing cycle. If you don't see the subscription listed it means you ordered through JVZOO. Just click the link that says "preapproved payment plans" as shown in the image below and you will see the subscription there. The direct URL is below: