SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d23b72393806c5cc9614d15e91e74554293a4a115303fb918ae348cd49a3740' 
  AND token = 'QdM3HxMUnjTZ4ci9IXF9V0hhWU9IbzuGmj5LhEDh+A4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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