Select count distinct on key column where multiple others satisfy condition
Create groups with GROUP BY based on account_id. Find the MAX of sat_cond1 and sat_cond2 for each group. If the MAX values equal Y for both condition, keep the account_id. Count the distinct account_id values.

Above translated to SQL:

select
  count(*)
from
  (
    select
      account_id
    from 
      data
    group by
      account_id
    having
      max(sat_cond1) = 'Y'
      and max(sat_cond2) = 'Y'
  )
;