The delay is caused by the system, so there is no way to programmatically change when the events are called.
However, you can:

Put the code inside draw(); so instead of a mouse event, put inside an if statement checking whether or not the key has been pressed...
That would be:

1. if(keyPressed) {
2.   switch(key) {
3.     case('w'):case('W'):y-=5; break;
4.     case('d'):case('D'):x+=5; break;
5.     case('s'):case('S'):y+=5; break;
6.     case('a'):case('A'):x-=5; break;
7.   }
8. }

Thank you very much, this helps a lot!