SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66d358220f08c279d566998a32d12206e5897e1cfc5fd05ec6d6463f5588649a' 
  AND token = 'wyzvQgMkYjG+qxhngKKxSmm7Bl+1XU6XcsTGf4dIsdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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