SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc3ff0c3b752ed01dd72da33fcdfba053ad908af4eacbed0fddaf6761537e39a' 
  AND token = 'LhVxRBO15pb+4qLe0UZ5Ioz3O2V/YDxvIxPKxKoMIiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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