SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae67d15f8c4368ff20c61b0ad52a97deae608ab6f12e9c5f55676945250d518f' 
  AND token = 'WuZWhHXtV738IHE1pZjAv+uDKC7KIQrQIZQvriCXWag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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