Utilize locks to prevent certain edge case issues

lib/lock.ts

@@ -44,7 +44,7 @@ export async function releaseLock(
   if (res.deletedCount !== 1) throw new Error("Lock expired");
 }
 
-export async function lockExists(lockName: string): Promise<boolean> {
+export async function getToken(lockName: string): Promise<string> {
   const res = await collections.locks.findOne({ _id: lockName });
-  return res != null;
+  return res?.value;
 }