bind BUTTON_Y "toggle timescale 10 1"
Just add that to a new line at the bottom of your codes, then push triangle to turn the speed off and on
If you wanna change the bind just pick one of these:
UP = DPAD_UP
LEFT = DPAD_LEFT
DOWN = DPAD_DOWN
RIGHT = DPAD_RIGHT
SELECT = BUTTON_BACK
START = BUTTON_START
TRIANGLE = BUTTON_Y
SQUARE = BUTTON_X
X = BUTTON_A
O = BUTTON_B
R1 = BUTTON_RSHLDR
L1 = BUTTON_LSHLDR
R2 = BUTTON_RTRIG
L2 = BUTTON_LTRIG
R3 = BUTTON_RSTICK
L3 = BUTTON_LSTICK