SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e240a34ad4af5e5c67c780acb1d769c5932ff34af72a56cffe0f7c030f917d0' 
  AND token = 'IInxh6nVuAM7wJ7UG/BFUz1mHz8QJcKZZkoY0eiGnDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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