SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f8553f61a8a5b242beb292010d2b13fe8a289711a85e45c79ff040aecc892a34' 
  AND token = 'VxVmlsF+COFyc9Vl+XVioe62UN2tLTnaqVgyGBtOjEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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