SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dac214bc1fdbd9c8806d891bed96fd456487380f1b74a8bdce5f56284e284ae' 
  AND token = 'QDGIWCQKODjIPQ+lYGkpNQ3fzPHHWyUmFln9i/E6Uyk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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