SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '150b6ecd19e48288c33a559fe43a8c9009d81be52f92c59a6618d541dd252c7a' 
  AND token = 'a5wpKWih4hHb4IXaqj9pQiOkJVHSODYnpEhhGYKmUlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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