SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '635c024c532056afbf3fdafe3c774713d0281c277df871f37759fd395ce328d7' 
  AND token = 'lXU4BU4SqYuIqdZ06A35BbctuTcDKK6LxtwlC8J4TVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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