Control time without delay() Arduino
If button is pressed: Motor A and B move for 1 second at slow speed == > Motor A keep moving but at fast speed and motor B stop. else: Motor A and B both stop.


I would do a quick state machine:


  STATE / button released: do nothing;
      STATE / button pressed: run motors a+b;
      STATE / run motor a+b: run motor a+b; if 1 second has passed, advance to just run motor a;
      STATE / run motor a: run motor a at fast speed and stop motor b.  


fairly easy to code as well.