Which query is less expensive / faster?

Hi all,

I have a couple different ways to get results out of my table
structure, but I'm unsure which way is faster or less expensive to
run:

Option 1:  Query a table of 4 million rows, on 4 indexed columns.  It
will return 1 row:

SELECT field1, field2, field3, field4
FROM tablea
WHERE field1 = $1 AND field2 = $2 AND field3 = $3 AND field4 = $4

Option 2: Query a table of 200,000 rows on 1 indexed column.  It will
return 800 rows:

SELECT *
FROM tableb
WHERE field1 = $1

Which one is going to return results the fastest, with the least
expense to the database server?