SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8920db3bb8debce488b1e1670f66691a9b0c1c6d5c523b4a99cb030595019f1e' 
  AND token = 'gVI7N+JqQZpKWlFwhe9ux6qrAt2m+tnGI62JVQ3hFRY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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