SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89400d6c9390cff1acc818b77faabfed882152f949b9d508a98b6a4116de8187' 
  AND token = '1tHqmM0JJigO6AKgIL9QREz1BVN9YeAIzERPAQAUiGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00062

JSON explain

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