SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd642c8ca7b41da880a8aae9719f9e7bb76e21699011fab6d06a742cff8eae241' 
  AND token = 'MEFBt5RaZcaGjaU+I4Wj6IvvywkcHCHBSl1MipQe2Xk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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