SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2313d4a159fd4c8affc4a145217cb59437d0bbf17b4145042cb12165d59f074f' 
  AND token = 'nd5WJw0o70OUE/cDbaJzCwEhFyFjui5y/uozLdrHVvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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