SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '61bdd6dd00c16c57d44580aafd527319cea947fccf19104ddb1539c51787049f' 
  AND token = 'GlIYCO9nlHtzFolTYq4SZw2B8/yKdwApDZrDF2RWzAs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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