SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '393a53eb7ebfa9789b69161857a3940eb44f981e6aab1bf22637033c753958ec' 
  AND token = 'iILGgtlhPG1ycYvfVkpzJb9ms03Zg0+JJcN8qpZ0luU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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