SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '409a2d7874f0661bcdccec6d2ac32000486f563c17e4c17d506f570064f4c0e4' 
  AND token = 'P70hPxxiwGIW31I43Da389Oh/qxdoOUYdOxx6bq08vg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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