SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3910069b6893c974bc8f00369713da5eb189e42a292a386df29fa89439fd0118' 
  AND token = '8BCY2Pq6na53LZGajeG3kqqBOt7BhxWR1Q+lnK+mm/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}