SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bfa1030b191d31478babdad5bfd164b97c397bb294ab6536a4b7a194cddcd93b' 
  AND token = 'x5JhVh8KtSnCLfOniToyBlAdxJi02nG+5WrNYZjBiW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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