SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c76afad82a1aba928a303bf6bc74c79ae715c5454d697cfe046bc1816546d77b' 
  AND token = 'QfHcC7hVfoPAyIbBIfefM9/qsbRBgYE+maHmZJpkqTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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