SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a8182cc781fa55b85210a9210ef50481a3a7287048fc06f3ed3ea6ea3144f189' 
  AND token = '6g1pjZLPS9GOOfzNiqDJhVQInkji9skhgph0uZ02Q/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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