diff --git a/server.js b/server.js
index e907631..3dba1b3 100644
--- a/server.js
+++ b/server.js
@@ -350,9 +350,9 @@ app.post("/public/assignment/respond", async (req, res) => {
         await client.query('BEGIN');
 
         const q = await client.query(
-            "SELECT * FROM assignment_pings WHERE token = $1 AND status = 'pending' AND expires_at > NOW()", 
-            [token]
-        );
+            "SELECT * FROM assignment_pings WHERE token = $1 AND status = 'pending' AND expires_at > $2", 
+            [token, new Date()]
+        );
         if (q.rowCount === 0) throw new Error("Acción caducada");
 
         const ping = q.rows[0];