SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fb54c87097691193b50106cdebbf18eef4e1d96a7800e5d41423a125f6b67f6' 
  AND token = 'uLsaYoTPsKCBkbvck57DELR1yM/Dcu36Uwbcd4ipWfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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