SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63e217ffa0a2f138e66dfa17f48e20a55acbc15774c87a8f52e9fadd93390ac9' 
  AND token = 'VDwgBl+zXZZ9D636DWCBGAmLweMNiLT+zuYVH2V4194=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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