SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '698f54fe0bac9d060fecd2520b8362faac1b771c6e02fab5d692df0acf54ec45' 
  AND token = 'ZKqysHnTQFOte6aujNraD3KVXZgxhphiBF/DONF6Oac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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