SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f84fed13e5e22346ea4f2ece93cbc1de4898f41c11e79c46392398635ff99ea9' 
  AND token = 'RTszi+GPKj8+Qt5tkjojDNmwYZzcUUIZIU/txsdYwP0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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