can read the rows, but if they want
to modify them, they have to wait until your transaction is committed.

If autocommit is set to 1 (the default), the LOCK IN SHARE MODE and FOR UPDATE
clauses have no effect in InnoDB. For non-transactional storage engines like
MyISAM and ARIA, a table level lock will be taken even if autocommit is set to
1.

URL: https://mariadb.com/kb/en/lock-in-share-mode/https://mariadb.com/kb/en/lock-in-share-mode/