SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78a4981f156b33b3723ff9c95f3314ecfc36c2e286c0cb45fe236bb4fcec02e9' 
  AND token = 'f7GAktXmE+cgI1mWqS9lpKv5fYcsBXEbwsF7IQcVpK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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