SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b268902c6c57660cf4eabd43a6d1dd2ebf243ed21ac5d45bd6dae1bfbe7058d9' 
  AND token = 'niOI48oYOX67qjYLxq3lnGthHwYo9E0PLf8NZHxJrMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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