SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa71233faea29bbf85f6fcf66a62ca2f105515e3dbf0c1d1e5199b742cc30300' 
  AND token = '0OrkUwNnXsz1IHkhATKZ4hMKtkveanqNm+3OeqHUZ/E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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