SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b824ac3af46a1935f23cfe59f68f81cda704e0b790fc7118f44e476a73b4f4c8' 
  AND token = 'gB4SLioGILgSVKiyD8PNvngRXHcYoj2hESagBIIkIIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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