use sql field names with tables where join happens

src/Repository/UserInChallengeRepository.php

@@ -57,7 +57,7 @@ class UserInChallengeRepository
 
         $select = new Select(\Container::$dbConnection);
         $select->where('user_id', '=', $userId);
-        $select->where('token', '=', $token);
+        $select->where(['user_in_challenge__challenge', 'token'], '=', $token);
 
         return \Container::$persistentDataManager->selectFromDb($select, UserInChallenge::class, true, $withRelations);
     }