SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c64694720e31fbda2cb69e4ae8c281e33a21370cdcd5682eb228164dd5f3d040' 
  AND token = '9Vt/OnEYNGn8nNBz2CDgNrlvrMyFn3JL+EIzZxlWj2I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}