SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45c7230458322def1012ebe46b89376fa883fc56e24a4f090f19052186c9294f' 
  AND token = 'Upw8/x4vmPLfYsKbO+uSsm84c3QygtTSBP7RRpqCS4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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