SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31ef184d0e49669ce4835a5cfb9d6dbdcbfb724f8e46e05ebd326ccdb109d544' 
  AND token = 'KISXxD+7YCEK/97zdBAMptMQidDCafHmb/khcEDF0DY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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