SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbdb9d1e6ff6d7812ad832768a93cac129bdd9a295eee47dfd32592663b40f3d' 
  AND token = 'a09Uy+PeeGq6f6Pz/z0GnuCSiFY/pAhC9MJPjPaL64k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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