SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd134a37401ef3b6b7d4b64f97924328d8a2c373a43dd3ae4bc3a36998104df00' 
  AND token = 'VncC5k4PiaraDzmClqtT6U3iqIO34wcq968h1SMnjGE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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