SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b69631f1d5abfaa327d5c632fa2a221675de31d8aa8816ecb0e4124421a08af' 
  AND token = '3khb49/CRIWRJejx9zvScppaQwGV9Hw7nY+EUuyz8i0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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