diff --git a/includes/callback_node_access.inc b/includes/callback_node_access.inc
index 2db6eeb..9357cc9 100644
--- a/includes/callback_node_access.inc
+++ b/includes/callback_node_access.inc
@@ -38,20 +38,14 @@ class SearchApiAlterNodeAccess extends SearchApiAbstractAlterCallback {
    * {@inheritdoc}
    */
   public function alterItems(array &$items) {
-    static $implements_node_grants;
-
-    if (!isset($implements_node_grants)) {
-      // Check if there are any modules that implement hook_node_grants.
-      $implements_node_grants = count(module_implements('node_grants'));
-    }
-
+    // Check if there are any modules that implement hook_node_grants.
+    $implements_node_grants = (bool) module_implements('node_grants');
     foreach ($items as $id => $item) {
       $node = $this->getNode($item);
       // Check implemented node_grants.
       if ($implements_node_grants) {
         // Get node access grants.
-        $result = db_query('SELECT * FROM {node_access} WHERE (nid = 0 OR nid = :nid) AND grant_view = 1', array(':nid' => $node->nid));
-
+        $result = db_query('SELECT realm, gid FROM {node_access} WHERE (nid = 0 OR nid = :nid) AND grant_view = 1', array(':nid' => $node->nid));
         // Store all grants together with their realms in the item.
         foreach ($result as $grant) {
           $items[$id]->search_api_access_node[] = "node_access_{$grant->realm}:{$grant->gid}";