SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e87199627f605874864f82c972fab701edc4546bbd3894957300b037a8c6166' 
  AND token = 'ZZc7Fed7Y6qaDJBknt3SMgAzZaUGqbq0e+PgzrWUPWM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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