For example:
SELECT * FROM table_1 LIMIT 5 LEFT JOIN table_2 AS table_1.id = table_2.id WHERE 1
Otherwise the engine takes all of table_1
You can do it by joining on a subquery instead of an actual table. Something like this should work:
SELECT * FROM (SELECT * FROM table_1 LIMIT 5) as subq LEFT JOIN table_2 ON subq.id = table_2.id WHERE 1