SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee4e674bff440c0840ddd3e9dbe1978a12e842a54cf300ffb75c317fa18892db' 
  AND token = 'Q7ke06Y9U6USvFSZO6FPOHTPXR3fMn2dISikDsIxvJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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