Once you have allowed a consumer application to access an Atlassian service provider's resources on your behalf, the access token issued to the consumer will be accessible from your account area of the Atlassian service provider application. This area shows all access tokens issued by the service provider to all consumer applications, to whom you have granted access to your service provider's resources.
You can revoke any access token from this area. Doing this prevents the applicable consumer application from accessing the service provider's resources on your behalf until you grant that consumer access again.
To revoke an access token,
Screenshot: OAuth Access Tokens page