OpenID Connect – Token Validation on client without call identity provider (IdP)

I am looking for a way to validate an ID token without calling the IdP. The client app and the IdP run inside a controlled environment. For this reason, I want to validate the access token from OIDC, provided by Keycloak, direct in my Middleware. For performance reasons I dont want to call the OIDC endpoint from Keycloak again to validate an existing id/access token.