SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa0ef169999bddc99b32d997b0ea51061aeab75e22bf0ae327144e51ddc85f37' 
  AND token = 'VZh22u64G9VjHsvLegw36p502aUHVkoUhnoLSgAwwek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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