SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9551b51243888d6d44e43365ae649ee4cb070e22664de5e3af5c831125217037' 
  AND token = 'WgMXCfqUh+H3b/p2XEkRNCaTM+MxmOwht8Pr61bmCV8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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