SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '10aad0ea4c695e06b44fa49c490031f3435d9b466d5666b25749f41fdca7db02' 
  AND token = 'kz7klp8ExMZEu+WvW8S1vezx70CZd33RFXPHhSNF4+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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