InnoDB spatial index is not optimal with ST_Intersects

DROP TABLE IF EXISTS t1;

CREATE TABLE t1 (

`point` point NOT NULL,

  SPATIAL KEY point (point)

) ENGINE=InnoDB;

BEGIN;

DELIMITER $$

SET @i=1000;

WHILE @i<=5000

DO

  INSERT INTO t1 VALUES (POINT(900, 200));

  SET @i=@i+1;

END WHILE;

$$

DELIMITER ;

COMMIT;

explain SELECT * FROM t1 FORCE INDEX (point) WHERE ST_Intersects(point, GeomFromText('POLYGON((3 0, 3 3, 8 3, 8 0, 3 0))'));

+------+-------------+-------+-------+---------------+-------+---------+------+------+-------------+

| id   | select_type | table | type  | possible_keys | key   | key_len | ref  | rows | Extra       |

+------+-------------+-------+-------+---------------+-------+---------+------+------+-------------+

|    1 | SIMPLE      | t1    | range | point         | point | 34      | NULL | 4001 | Using where |

+------+-------------+-------+-------+---------------+-------+---------+------+------+-------------+