I imagine so too. You’ll be able to interate over the users in order and hit an instant index on contact method.
select
*
from
user
where
exists (
select
true
from
contact_method cm
where
cm.contact_id = contact.id
and cm.method = 'phone'
and cm.primary
)
order by
created_at desc
limit 10
—- partial index is even faster
create index primary_phone on contact_method (contact_id) where method = 'phone' and primary;