SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2cbaaed0a44aca142a6145309818638fbaa1fff90313b4891e05c859f7f384cf' 
  AND token = '9fQKMCnGMktRoKjW+NPvF8lyQSoLArp82crqP3kblDU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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