SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00d8f397a65f4febf304041514130f9e4b76a5bd0fa7478625ee5e469e44b0e7' 
  AND token = 'qWOySxBuNILIejRSiOf+i1qvBtFNLCLfCe0EJcTcV04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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