SELECT Counter.`99999910`.timestamp, Counter.`99999910`.wert, UNIX_TIMESTAMP( Counter.`99999910`.timestamp ) AS unix_time, alt.`statusanz`.wert
FROM (

SELECT c.timestamp AS stamp1, max( a.Zeitstempel ) AS stamp2
FROM Counter.`99999910` AS c
LEFT JOIN alt.`statusanz` AS a ON c.timestamp >= a.Zeitstempel
GROUP BY c.timestamp
) AS jdhhe
LEFT JOIN Counter.`99999910` ON Counter.`99999910`.timestamp = stamp1
LEFT JOIN alt.`statusanz` ON alt.`statusanz`.Zeitstempel = stamp2
LIMIT 0 , 30