SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ea5d1cd50e72b6f0d1dc6603ac7e2acec378283e1d361376ad2c92a0470ad1e' 
  AND token = 'l7cHJy10mQbbbNcUKz7odvmtt/A5bcaB82hxW1RIMdE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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