1. This is the full tracking of your parcel:
China Post Register Air Mail Tracking System
Parcel No.RJ842145060CN tracking result
2016-08-30 18:59:35.0 Yiwu city international eCommerce dept. received
2016-08-30 23:15:50.0 Yiwu city international eCommerce dept. customs scan
2016-08-31 07:50:07.0 leaving Yiwu city international eCommerce dept. ，next station Yiwu
2016-08-31 14:31:22.0 Yiwu Transit Station export security scan
2016-08-31 14:44:13.0 Yiwu Transit Station export customs scan (domestic transit )
2016-09-05 14:29:08.0 Beijing Transit Station export security scan
2016-09-05 15:25:20.0 Beijing Transit Station export customs cleared
2016-09-05 22:59:00.0 arrive Beijing Airport
2016-09-05 23:00:11.0 leaving Beijing Airport going to next airport/seaport

2. I also found this:
International Mail# RJ842145060CN Tracking Result
Summary
Tracking number Origin Destination Status
RJ842145060CN CHINA MEXICO On route

History Detail
Local date/time Activity Location Remarks
30-Aug-2016 18:59 Received by Post Office 32206600
05-Sep-2016 15:43 Departure export customs BEIJING

3. So your parcel in On Route to Mexico and departed China on the 05 Sep. May I suggest you read this for your country:
http://track-chinapost.com/China_Post_Arrival_Time_Stat.php

4. Your parcel is fine you just need to wait for it. When it arrive in Mexico, I suspect you will be able to track it through the Mexico Post.

Hope this help.