SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '194e2b1bdf2cbcfcb30b449c0cff76f46f2cb3d6cbb6fc2af3302b22fb0e16b3' 
  AND token = 'fodBYj9NZdrpYVfCL/iDYUnwgBLRtkE7Y4aznL7KCC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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