SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '902681384470e9b320ae1f5b2460882be4f107bcb778ffb85165dc502931e8b7' 
  AND token = 'Wg4JpUaOXdZ9STO48eSTzMqvEndK+lsuBDpjreDVxOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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