SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e18b84d560412b945d0dfd6ab9bb66105f716b1d06684e74805724aa3719f8a2' 
  AND token = 'vr0ADkaLan16dWQT6bc6YtbUrw/tTkK6KF8uP30XVkI=' 
  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