SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '468abf840c2364730c0c3933c5b625f148648c14cd16effd52d1f38c6d2ead41' 
  AND token = 'C0TzbSfuviP1rSBUsVVPscdGGNdEdlP4vieh0J0tGQ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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