SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02cd131ac8742e915ff09bd6a283f84356e07e007dfde01304a83db56a763846' 
  AND token = 'pZncnVR7w24hIaUyRt/bzO22yQhw7MazRcWNTkmfStM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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