SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b73045fe0ee34cdad4ce21424998000d89e2cd2817a704ff5bbe89563c82bda2' 
  AND token = 'WLzZwLjGGtroTzfVVg/CRegVO2A6B8LBZbPfFwn6cdw=' 
  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"
    }
  }
}