SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6f4bf600644d59f1758c8b831c683c72ad3b99f04005c7edf9b95ec5d1ec34c' 
  AND token = '91UchMT/D/xBSaVKK5OFGeTEQPdW02l2RxzmbJZxvfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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