SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3020790e10de27485a91ee5994f7329c1bd4edd03d402ca0e895538860e337fa' 
  AND token = 'rIAK7bFijoQUi5A6Pqj1aDEWcazQxX5AHvLeDVxtzdo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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