SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ffe4dacba8d2610cd368640596524ff64d42299f751861b432880e9f28f6f06' 
  AND token = 'QwsF5J5u67WqpXExR1e5BerOTSjskgiwfmSq5myVc8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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