SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ce4ff0ac3197ddec412229e9feb34d8bbf7b506d7f9c1873703058b54daffe' 
  AND token = 'fC/h9mXNjqsFu4PZdoIKFmXkLEQSfZOHYhNuKmJo9g4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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