SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b28149d68ee81911a886edbeb01e6267bacc8c57cddd9d46200b75bc481ccf9' 
  AND token = 'zbozHP8ZZmjwaNSz9mRj3sthPFsbCJIhB4cq0ompgb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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