SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '60e2ab31b4929c92599f013f6ab137aa94174572a498f13befe6d14fe5d15e29' 
  AND token = 'hRbesHwDRJr+/ZkO+asl1SAWuQHAhOB42GiY3PkfcnA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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