SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a005deaa51d0de9c5bbce5055a4503420119ee8638168ea4bf6de47313bb457' 
  AND token = '4FNpWZzGcf8aK/seJPkecQINOYe5LSFXGzGGjlxDnx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}