Anyway to index array with other columns

Given table below, is there any way to index  field_a, field_b, array_a?

Create table table1 (

field_a integer not null primary key,

field_b integer not null,

...

array_a text[]

)

My app is running queries similar to this:

Select * from table1 where field_a = 123 and field_b = 456 and array_a @> ARRAY[’tag_xyz’];

The array_a can have unto 1000 elements.  Currently these queries get very expensive if the array has any length to it.

Thanks for any ideas.