SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce09fd5517d95ec0a49ebf1eabccf112da8125cb4427d967bdf549eefb424b42' 
  AND token = 'av2Y0hJRyZxruYsBEK51CBomE6atHXQFlCG9wul4LTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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