SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '652f7eaa4a3f383998d88073f61f6f337aa1d7f33b77dcc911cd55ec39fe060f' 
  AND token = '0JhtMh7gc3qhnV91LHtzbzeiHn9TppO1ZAGZQhiK4wc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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