SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb61f05e9676766490cc0004d450f759afe13c9f18b3a48f4a81bdbd9789cac1' 
  AND token = 'UurfczJl8qWA5DLLSjRnKGcBKb8nPrUeZc1gpUOByW8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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