Du kan använda INNER JOIN
för detta,
SELECT a.pid, a.name,
b.sname,
c.time_from,
c.time_to
FROM person a
INNER JOIN specialisation b
ON a.sid = b.sid
INNER JOIN Timing c
ON a.pid = c.pid
WHERE a.sid = 1 and
a.name='ABC' AND
c.time_from >= '08:00:00' AND c.time_to <= '10:00:00'