select * from info_table info
left join main_table main on info.id = main.info_id and cond2 = 'cond2'
where info.id = 'cond1'
SELECT * FROM `regions` WHERE
' . $x1 .' > LEAST(Ax, Bx) AND ' . $x1 .' < GREATEST(Ax, Bx) AND
' . $y1 . ' > LEAST(Ay, By) AND ' . $y1 . ' < GREATEST(Ay, By) AND
' . $z1 . ' > LEAST(Az, Bz) AND ' . $z1 . ' < GREATEST(Az, Bz)