SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d4da094b6e963f554761b8c7bb14ec7fd28b2d84c5918a640a3303221967e5c' 
  AND token = 'H24G3oemA9ZkjRcLvqYQv/t7m6sNQSgq8YuKpKwFUFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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