SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '106afbec10fb370aa64240374aaeb6e592da1fdb9a7d1c6b90116e8383821cdf' 
  AND token = 'gj1Hs0EGKOxiISLlw2SJ7gEtuv1oGXuRfCq79vYNpUw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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