SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46adcf56a8104ca8b0552790688069db73601919ff2ec8cafcd65eab008a9bc0' 
  AND token = 'MvRT3drLom3+VGGpw7JwYbSnYsluxN5zMH43Hrjqrfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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