A full start-up of the TV Box takes between 1 min 15s and 2 min from a powered off state or from a “deep standby” state.
From an active standby state the wake-up is much faster, only a few seconds are needed.
Depending on your choice, the TV Box is going into Deep standby after a certain period in order to save energy (less than 0.3W in Deep standby = “ECO mode”). In that case, waking up from Deep standby will take more than a minute. If you prefer a fast starting box at all time, you may disable the Deep standby via the Settings > System> ECO mode / Deep standby.