SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60208160e3e39098155c7ad155dc2899d5f2034fd367dd90f6aa5b67aaf80a06' 
  AND token = '8y5PIsk++stXXZrBh4VDFkMpG3lwfmpQ5q0FRkAcP/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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