SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc59f6c490aa9579de237805d36b417c21ec6e5e791cfedae1bd6b379dbabc46' 
  AND token = '1WjoBA7GQ/J6gKRLqLMWkGUWVC9WmmjYgtvPRkX2u7w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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