SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddaab2f677149214e8f4c47f65a7389f6200ad0c621cac3be0598075cd865526' 
  AND token = '3A421SWfk9Y33N9bohA+H3MsheTp0qWxBA9Ss3HUg8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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