SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6692dbc5adb57c2d1791c464d4734df719ee4da2f1463b3aff27849e2118e438' 
  AND token = '8iuGJof0SFHQgwdFDMLSNG+BhQoZ4IJKFvU79+O+N/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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