Remove optional, now is not optional

freqtrade/persistence/models.py

@@ -684,15 +684,12 @@ class PairLock(_DECL_BASE):
                 f'lock_end_time={lock_end_time})')
 
     @staticmethod
-    def query_pair_locks(pair: Optional[str], now: Optional[datetime] = None) -> Query:
+    def query_pair_locks(pair: Optional[str], now: datetime) -> Query:
         """
         Get all locks for this pair
         :param pair: Pair to check for. Returns all current locks if pair is empty
         :param now: Datetime object (generated via datetime.now(timezone.utc)).
-                    defaults to datetime.utcnow()
         """
-        if not now:
-            now = datetime.now(timezone.utc)
 
         filters = [PairLock.lock_end_time > now,
                    # Only active locks