You could perform kegel exercises to improve your ejaculatory time. THe only other solution it is to take a drug like viagra but that is not recommended.
Pelvic floor excercises are performed as follows
1 Contract your muscles like you would if you wanted to stop a fart.
2. Hold for 5 secs.
3 Release
4. Repeat 20 times
5. With time increase to 100 - 200 times
You should see an improvement in your holding time