SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a02e800cc2783c87f8f4171f0711a8ea9f296bd6f834af5c0bb7efe22fc3097' 
  AND token = 'rFbjckhjhCHkVt1HUAhxSI8mMUcRg5Xtmn768P/2hjI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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