SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1ffd31fba506ff96ef1fe77315f1e660a55078cdb098e9a8e365bd09ddeb5070' 
  AND token = 'PaJTj5LvEiIketXAzPCpfHrJanqjPV3VgScQltYDZWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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