SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94e671226afef2a3661d7687c3a9b3d34190fcf5c8578bd8d6e24a3de337e510' 
  AND token = 'XWQDPF4CvJiRDkGDwGSCYYjoYuvBiYGORm4g2jyBgaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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