Combina due query MySQL in una

Non puoi ORDER BY nel tuo primo SELECT e poi UNION esso.

Modifica
Puoi comunque

come nella documentazione MySQL UNION

(SELECT a FROM t1 WHERE a=10 AND B=1 ORDER BY a LIMIT 10)
UNION
(SELECT a FROM t2 WHERE a=11 AND B=2 ORDER BY a LIMIT 10);

Che poi rende il tuo SQL

(SELECT clicks FROM clicksTable WHERE clicks > 199 ORDER BY clicks ASC LIMIT 1)
UNION
(SELECT clicks FROM clicksTable ORDER BY clicks DESC LIMIT 1);

Modifica 2
Per restituire in un array

SELECT (SELECT clicks 
        FROM clicksTable 
        WHERE clicks > 199 
        ORDER BY clicks ASC 
        LIMIT 1) AS NextClick,
       (SELECT clicks 
        FROM clicksTable 
        ORDER BY clicks DESC 
        LIMIT 1) AS TopClick;