SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa109d183c5b207ab2bedf40d459298f8f74245350f6bf83d11f7c12dfbb015b' 
  AND token = '4Kj+9OFmtZafiSudSTOPapqrvkKgnUsDd8vjLz1eHMM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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