SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a3d2fded75757f8bdbea94bd801b9f00bc451423cbd97b2dad73453abe70824' 
  AND token = 'A9pzyHOvOMbrtxH9WG72R7WGRd7hEf8pxllsxYHAcRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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