SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8b8fdf6ba3bb48b3af70afdc8e0725e6ddf7379bfffa78be08270205894f910' 
  AND token = 'Y5xjMQBtgY/RVFsICv2XcpOIVhPnrPF1kyvrnBYLYqE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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