Você pode sair do loop usando GetKeyState () e break assim:
Loop, 10
{
Click 745,664
SetMouseDelay, 100
Click 345,635
SetMouseDelay, 25
Click 878,471
SetMouseDelay, 25
Click 772,557
SetMouseDelay, 25
Click 552,387
SetMouseDelay, 25
Click 578,516
SetMouseDelay, 150
if GetKeyState("Shift", "P") ; Looks to see if Shift is pressed
break ; exits Loop
}