SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dcbbd4e6d99b45b832777672fbde030f12f3358210b3817f2efd9f789b29df4' 
  AND token = 'j6wGttiPs6H3LwCHmGGhAkvudyR2jzqgcOh/L+CwA7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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