SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '52db729379b89cd3130786579e6f7bb32f7555ede42a77b7a15dfc003e974793' 
  AND token = 'qNfMIZrRnf6ymldf+oj6qOuFIqY1kcmtXTr04japtY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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