SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59654a91a051988c92c4bebe4ad11df839d0281f769e6e97c718dcef76d9efb4' 
  AND token = 'hPVHrjxF+Os8DDhB8lKx3ouxrbYOYlaFLIaoBWVwotQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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