SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4252b7708740e1f21b1561cf72e62a7a279f7ece1a39e08e048f4f9bcc580ed9' 
  AND token = 'hYsA3tLcSH0Mb9Xfd099T2F1jGnxlLAfUvSifnomKFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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