diff --git a/api/components/OAuth2/Storage/SessionStorage.php b/api/components/OAuth2/Storage/SessionStorage.php
index 8777f96..c056f9b 100644
--- a/api/components/OAuth2/Storage/SessionStorage.php
+++ b/api/components/OAuth2/Storage/SessionStorage.php
@@ -52,7 +52,7 @@ class SessionStorage extends AbstractStorage implements SessionInterface {
             ->andWhere([
                 'client_id' => $clientId,
                 'owner_type' => $ownerType,
-                'owner_id' => $ownerId,
+                'owner_id' => (string)$ownerId, // Переводим в строку, чтобы работали индексы, т.к. поле varchar
             ])->scalar();
 
         if ($sessionId === false) {
diff --git a/console/migrations/m170415_195802_oauth_sessions_owner_id_index.php b/console/migrations/m170415_195802_oauth_sessions_owner_id_index.php
new file mode 100644
index 0000000..08541e3
--- /dev/null
+++ b/console/migrations/m170415_195802_oauth_sessions_owner_id_index.php
@@ -0,0 +1,15 @@
+<?php
+
+use console\db\Migration;
+
+class m170415_195802_oauth_sessions_owner_id_index extends Migration {
+
+    public function safeUp() {
+        $this->createIndex('owner_id', '{{%oauth_sessions}}', 'owner_id');
+    }
+
+    public function safeDown() {
+        $this->dropIndex('owner_id', '{{%oauth_sessions}}');
+    }
+
+}