MySQL Forums :: Performance :: Long execution time despite LIMIT 3

Something unobvious is going on, please provide
* SHOW CREATE TABLE tbl\G -- engine, indexes
* SHOW TABLE STATUS LIKE 'tbl'\G -- sizes
* EXPLAIN SELECT ...\G -- clues of inefficiencies
* SHOW VARIABLES LIKE '%buffer%'; -- cache size
and surround them with [ code ] and [ / code ]

Also, please do
SELECT COUNT(*) FROM table WHERE thread='foo';