SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cbce71670c1167e54475d01976cbfeb2569c9757d79ab612ff57b091a3df16cf' 
  AND token = 'VJrGw6FhtNju+PN66WzVFgNaYZ6aJKlGiKdcSiDlCv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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