SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47a70a68f422c5745f69ddafb138b68f628cca7f90bbc1ede36580100922c362' 
  AND token = 'VVux3zWVlMvBzRs5LvDKpNSFtGdVZ9EHFK9i51xdIxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.01327

JSON explain

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