SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48746f691267e8696976591862ef34c19c46f5cbc8e023d766f3d2df5feff52a' 
  AND token = 'VYmjrdPXnZoJI/iueGKaerJfWzXrZdk6iniaP/XhDTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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