SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cef0c3623249f00227b456d8a41310850ce268867d2f1b6cc1447f016d25875c' 
  AND token = 'MKyF+fzob1MpPvtmlsxBXb4RI9v7YukTJqDFiVrjn9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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