SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24a28e3b39765f5d342814ec02a208b39e63ca5a4e70ecdf7f41c0c49059077d' 
  AND token = 'uc7ByHwe2pgJC5YjXK1HqOC6pDdYRyHqwKhD6gJVFVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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