SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'badff23e63ef25120c10b420cd9917a0584db8b3a4c7be0a069dec8a5a91ab54' 
  AND token = 'wPKGveIJOkzlWg45KXIjLawyIUGww09ReAQ0ajFASSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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