SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f5f952914388c2af579cd454e2483e52537c4190815fdfcdd775ea670561320' 
  AND token = '2gh5pblc0+60POwOZNoBQMgqR1pZgSQZf6MAy0h3c0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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