SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23c2c16e2372d44a0a22441dc123baf4ebd6170ec5337605fc154124b532b4da' 
  AND token = '/ZCkcbrgjW86GnqQaVBL8vEzy8kSHuYn8578nM7osvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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