arrays in where

I have a table....

select * from history;
idx |       tokens
-----+---------------------
    2 | {10633,10634,10636}


And the values in the tokens field are taken from sequence values
from another table.

Can I use this kind of storage to identify all the tokens in the
first table that make these token_idx values?

Normally I would store these under a table with a structure like:
2 | 10633
2 | 10634
2 | 10636
as a "join table"

and simply join all these rows together.
but I'm curious if I can use the ARRAY and if it might save me some
performance because this join table would also have a lot of
redundant data...