SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd14f7f24978151bb68bb1f8843a7f88f2f031ea86f32dd396314ea650e694fe' 
  AND token = 'kwRoXk9FGvP21y4IHYINfooK7+RUkhmVVaQ4jR6u3fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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