title: Is it possible to avoid huge number of access tokens in database?
body: <p>I've built a RESTful API with a Laravel Passport project.<br>
  It's using the Client Credentials Grant to authorize my third party project.<br>
  The problem is that for each api call from the third party application it generates a new access token.<br>
  By the end of the day, if i had 999 calls i will have also 999 new records in the oauth_access_tokens database table.<br>
  It's possible to avoid huge number of access tokens in database?</p>
  
  <p>Maybe in League\OAuth2\Server\Grant\ClientCredentialsGrant.php:</p>
  
  <pre><code>public function respondToAccessTokenRequest(ServerRequestInterface $request, ResponseTypeInterface $responseType, \DateInterval $accessTokenTTL) {
      $client = $this-&gt;validateClient($request);
      $scopes = $this-&gt;validateScopes($this-&gt;getRequestParameter('scope', $request));
      $scopes = $this-&gt;scopeRepository-&gt;finalizeScopes($scopes, $this-&gt;getIdentifier(), $client);
      // $validToken = query to check if $client has existing token neither revoked or expired
      // if ($validToken) { 
      //     return $responseType-&gt;setAccessToken($validToken);
      // }
      $accessToken = $this-&gt;issueAccessToken($accessTokenTTL, $client, null, $scopes);
      $responseType-&gt;setAccessToken($accessToken);
      return $responseType;
  }
  </code></pre>