SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02c68788d108b41ac236a023b42f5fa38b7bc17aa9ad04fcf5ee2ad29e582d44' 
  AND token = 'dYXQbyYe/L9twnPz9436TBBY42QkMEj6AgvjqOZ+GQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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