SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00b791b6cb76600e7bee70062e11422825b0bd737eafccba915f2ffaad3980e4' 
  AND token = '9GnHYaEc4+tPBsYvTQXdlaBFAjxMoNy1Z3WBinwjgSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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