SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a614744811b76f78464e3ab1dbf8dc6f94e84342427afa532ec8653be3ccc4da' 
  AND token = 'Jqn7XD78uI0qqBS1FLZipQKAk2mlj6KFhdxaIJsqte4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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