ASP.NET-MVC – IdentityServer MVC token expire

new Client {
 ClientId = "mvc", 
 ClientName = "MVC Client",
 AllowedGrantTypes = GrantTypes.HybridAndClientCredentials,
 ClientSecrets = new List{new Secret("secret".Sha256())},
 RequireConsent = false,
 AccessTokenLifetime = 1,

 // where to redirect to after login
 RedirectUris = new List{"http://localhost:5002/signin -oidc"},

 // where to redirect to after logout
 PostLogoutRedirectUris = new List{"http://localhost:5002"},

 AllowedScopes = new List
 {
 StandardScopes.OpenId.Name,
 StandardScopes.Profile.Name,
 StandardScopes.OfflineAccess.Name,
 }
 }

{
 "nbf": 1474697839,
 "exp": 1474697840,
 "iss": "http: //localhost:5000",
 "aud": "http://localhost:5000/resources",
 "client_id": "mvc",
 "scope": [
 "openid",
 "profile"
 ],
 "sub": "26296",
 "auth_time": 1474697838,
 "idp": " local",
 "amr": [
 "pwd"
 ]
}

var user = HttpContext.Current.User.Identity;
 if (!user.IsAuthenticated)

I am new to Identity Server, and I am missing a key concept in my understanding.
I am using the code of the MVC tutorial.

If I decorate me with the attribute [Authorize] Home controller and visit my website, I will be redirected to IdentityServer. Then I log in with my username and password. Then I use some custom code and authenticate. I get an AccessToken and then I can access the Home control

My client settings are as follows:

new Client {
 ClientId = "mvc",
 ClientName = " MVC Client",
 AllowedGrantTypes = GrantTypes.HybridAndClientCredentials,
 ClientSecrets = new List{new Secret("secret".Sha256())},
 RequireConsent = false,
 AccessTokenLifetime = 1,

 // where to redirect to after login
 RedirectUris = new List{"http://localhost:5002/signin-oidc"},

 // where to redirect to after logout
 PostLogoutRedirectUris = new List{"http://localhost:5002"},

 AllowedScopes = new List
 {
 StandardScopes.OpenId.Name,
 StandardScopes.Profile.Name,
 StandardScopes.OfflineAccess.Name,
 }
 }

My access token is

{
 "nbf": 1474697839,
 "exp": 1474697840,
 "iss": "http://localhost:5000",
 "aud": "http://localhost:5000/resources",
 "client_id": "mvc",
 "scope": [
 "openid",
 "profile"
 ],
 "sub": "26296",
 "auth_time": 1474697838,
 "idp": "local",
 "amr": [
 "pwd"
 ]
}

When I set AccessTokenLifetime to 1, my token will be invalid when it is sent to call API etc. But I can still Visit the website.

What is the best way to let the MVC website confirm that my token has not expired? This may be where the refresh token comes in.

Note
AccessTokenLifetime is set to 1 for testing only, so I can test quickly.

Maybe so?

var user = HttpContext.Current.User.Identity;
 if (!user.IsAuthenticated)