SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da599636bbab88f461cee9af5c44a112041d994cc2ba04b72ee2dfa63f0956ae' 
  AND token = 'VVYbhc6lJBNWMGWkKDlEhWOG497hAhqRHVhdlQgO8tQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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