SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dbb69f9b279dd49d75199c7bba983806057a2f2124b11823695d0e4310522f00' 
  AND token = 'hmFUqWAx3Rqz8KbnCFRY5jpr+PDlxVgAGDkUE8PqxDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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