SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd58d19d5752b61de597962c227d58cd7c947be471b35411ef364a6cfd0a9d4e3' 
  AND token = 'KdSROajBp9qaiJVIPZeLmfXvrtTjVG4QTWG9QvNgfrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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