A test in mysql-test/r/derived_condition_pushdown.result assumes that 2023-05-06 is a future date:

“
PREPARE stmt FROM "EXPLAIN FORMAT=tree SELECT *
FROM (SELECT NOW() AS time FROM t1 WHERE f1 = ?
UNION
SELECT NOW() AS time FROM t1 WHERE f1 = 0) AS dt
WHERE time <= ?";
EXECUTE stmt USING @a, @b;
EXPLAIN
-> Zero rows (no matching row in const table) (rows=0)

SET @a = 2;
SET @b = '2023-05-06 16:49:45';
EXECUTE stmt USING @a, @b;
EXPLAIN
-> Table scan on dt (rows=2)
-> Union materialize with deduplication (rows=2)
-> Filter: (t1.f1 = 2) (rows=1)
-> Table scan on t1 (rows=1)
-> Filter: (t1.f1 = 0) (rows=1)
-> Table scan on t1 (rows=1)
”

Obviously, that's no longer true. I think we can change the year to 2033 for now, and how for a proper fix with the next rebase.