SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a259cc5abe64122068c156436f0a7bb032f132d868f4fa582ff0d54d148bf01' 
  AND token = 'm+iz90OMHA4qHvnSdTCx0JCOMIXQQexT7aE2T9R9fjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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