Fix touch() a bit

redis_cache/backends/base.py

@@ -366,11 +366,15 @@ class BaseRedisCache(BaseCache):
     @get_client(write=True)
     def touch(self, client, key, timeout=DEFAULT_TIMEOUT, stale_cache_timeout=None):
         """Reset the timeout of a key to `timeout` seconds."""
-        key_timeout = (
-            None if stale_cache_timeout is None else timeout + stale_cache_timeout
-        )
-        client.expire("__fresh__" + key, key_timeout)
-        return client.expire(key, timeout)
+        fresh_key = "__fresh__" + key
+        key_timeout = timeout
+        if client.exists(fresh_key):
+            key_timeout = (
+                None if stale_cache_timeout is None else timeout + stale_cache_timeout
+            )
+            client.expire("__fresh__" + key, timeout)
+
+        return client.expire(key, key_timeout)
 
     #####################
     # Extra api methods #