SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e929bc1d8b0c772b232873c67b9ed2a85332e5e74161e4c5f56d8ccfcea871e4' 
  AND token = 'uyEHvIepn4OQLVvJYqBOckOnGK8NBdsf7qX8f/i+zTw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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