Update app.py

app.py

@@ -210,23 +210,7 @@ def select_key(request_type, model_name):
     根据请求类型和模型名称选择合适的 KEY，
     并实现轮询和重试机制。
     """
-    if request_type == "free":
-        available_keys = (
-            free_keys_global +
-            unverified_keys_global +
-            valid_keys_global
-        )
-    elif request_type == "paid":
-        available_keys = unverified_keys_global + valid_keys_global
-    else:
-        available_keys = (
-            free_keys_global +
-            unverified_keys_global +
-            valid_keys_global
-        )
-
-    if not available_keys:
-        return None
+    available_keys = valid_keys_global
 
     current_index = model_key_indices.get(model_name, 0)