SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea6ab997580036094c0715295483f58106e5f68cedb3b6fe05f9d9f4223c8336' 
  AND token = 'rj4Ryi/fklaI3hYZVNXaHUt5Zsq5UtAOSgPP+3wlGLM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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