SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b3ac4eb07e34000116d28b16972daf5b7928f5f545f8cbcb326af3c13f8c4f7' 
  AND token = 'yphKTeNte/uDIcOvXAENvBwFCBBzWd2YPPfjLJ6ZpMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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