SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '589c65749a48110113030fcaec56390dcf95635d7b6fa4192717b00285ea496f' 
  AND token = 'Vw2v+oGjZ1mycWgXyUsaBSug/q2hWEs6VcYkHuQYSQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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