SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0407e1b69356936a0635758bb12b6b8479043b6d2187df3c69ebe90bf91695b2' 
  AND token = 'n0OhN2qe1UtTkrwzvEfGasHQJefVXhipfQVwogJF974=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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