In general, the copy will have the same power and toughness as the token. This is because in this case, the token's power and toughness are part of the "original object", so that copy effects can copy that power and toughness (C.R. 613.1, 613.1a, 706.2). Although this is the case for most copy effects that copy permanents (such as found in Clone or populate [C.R. 701.30a]), you should note that some copy effects specify that the copy will have a different power and toughness instead (C.R. 706.9b); examples include Quicksilver Gargantuan.
What power and toughness is a copied token that has X/X