SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6786ba82f753d937eacd2f0ba2f141b27a7ca8564a131e17429f77eb8b560e1b' 
  AND token = 'lhknxlb/7Oo18WTW0Wp/av4TtQK83L1wBWCiI36epRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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