SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a48bf1d7a55c875a7b4043d9d98044c160a4fe658860784aa808a134b6f8c4a0' 
  AND token = 'i/bod5KNbuBUcj1ywqkKClHwEZUaLARSJxzStipRAXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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