SELECT COUNT(*)
FROM
((SELECT
`token`,
`timestamp`
FROM `trace`)
UNION ALL
(SELECT
`token`,
`timestamp`
FROM `trace-article`)
UNION ALL
(SELECT
`token`,
`timestamp`
FROM `trace-search`)
) `trace+trace-article+trace-search`
WHERE `timestamp` >= DATE_SUB(NOW(), INTERVAL DAY(LAST_DAY(NOW())) DAY);