SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef9b56d969ad7f3a6bb020d7b989481251a96cfdae853a6542e2985a04f2d604' 
  AND token = 'sS0xSQOiQGKNB9hsiH4OsfzWD/6n2XVrKwLqwtp1vrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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