SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c18ddeafb479763ee05830c009c20a2b426ece4e514e9fc27355c8b1fd64e56' 
  AND token = 'VOFgQDrwLX5uvyGewDHCKr8fJJMmoHT5gvddzhYrpoM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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