SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df9eb28fc54070d8fa66960b5c59a691d52cb49e1b539b04c05077c1ad701e77' 
  AND token = '0vqx/L7kpip0BVK1lCzOlAJf32fhKT+DAwFJtwrB+gA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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