SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a24a856a2dce84b457207f136472015cf2ddcf468171327799690a926c7d39b2' 
  AND token = '3hZMgw2KoGt1XqXfN2EW5lO1mEbTwI6jlJQ0Z+KqfWE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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