SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b5e3e0ee5611e07bda8be2e84e1b47da1773bdc8e5433660cc98f4263a5515d' 
  AND token = 'Qj3b9n391aud/z+QHY8eb+vk5hgub8MsnT4a6icRmUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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