SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e2477588575814e6cb825a8929857a1a273ffa6d6a34e390535ac861b014d278' 
  AND token = 'PN4TrjNanQ2g/gfVc08cIwh+erN9BOJjUq8Q6l+Is+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables