SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '46d52bcc500d7dded8e1f1a24c4443fd49c267301bfd12a775a719a492c175a1' 
  AND token = 'YXaY2eNkKPk3HM3f5/sv8OucMVeet03VWnbMhiudlrE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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