SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd85ab081863cd9e211c6accacc96660026d10227ece1526379f0a6e5fb126721' 
  AND token = '2m30F3U4ZFzLk+mgSbxx1BaaImnNhn77BC4CKMMuyBs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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