SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '142d66511dfe4ace52600c9d0f744b29599afb1fae72c043043fa858f7df7303' 
  AND token = 'Yuu1DGbyRNhPMMJiJycYyu79XWbDlQNsn0WSND4HIzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}