SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff08301a4506c08c23bd9ab04b9874235459732b86654fa0c93e9900e1b3a4f1' 
  AND token = 'l9dLS8Wk1Vs4csWwNjLPt/qpCLKt9H2YROrhYphh3hY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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