SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4fc4679fa553674d570adaa1a990da12f8b405d59065292d35ae4707a4cd7a8d' 
  AND token = 'ySmmQSPNzl36QwVEcDlj37GXUZHzBPH7RGwRNln1Zic=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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