SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cc532b5dde9e0c9fccb93fd21a05b5ae0fd0d3fe4089fe1ecea16e7bdae87f8' 
  AND token = '6oUWHGEbgPSV+aIqQSQF9wmX0UOkxfaOIQx5XA3y+xw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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