SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '731865c02612c226036dcd4a2dd359b089eefac7379b6478286eeda772c25907' 
  AND token = 'iSgOtgn5UpAULJd8EaFJK7i9ZlZU/E3VphFhkFeNZbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}