The asyncio package has been included in the standard library since Python 3.4.

--- motor/frameworks/asyncio/__init__.py.orig	2016-10-26 16:39:52 UTC
+++ motor/frameworks/asyncio/__init__.py
@@ -25,10 +25,7 @@ import multiprocessing
 import sys
 from concurrent.futures import ThreadPoolExecutor
 
-try:
-    from asyncio import ensure_future
-except ImportError:
-    from asyncio import async as ensure_future
+from asyncio import ensure_future
 
 CLASS_PREFIX = 'AsyncIO'