SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a213569a855f2e9696b57a797f28d3de68561650c04338974f24a6a4475ed573' 
  AND token = 'ePEafTGAnZgBBbMVIb64XDJ3dj4MzQyrDLXE2q9LIKQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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