SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98a3e3778917203d5f6f952625dcaa0866a8f75a819be32499debb11ce5a9b8e' 
  AND token = 'WmNFnJB12vvAErbYlWhNQO9l2dasQpbXaGDe+luOmUA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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