SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0afcbf4f4ce513c9a5475439a28551b3800659f00b2d5d76e99961af8064fc44' 
  AND token = 'eC3ndQ2g9nSaziP7JZ46ZwCIpkKIZiVRKuOJSfQ0VDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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