SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f61529a9e019959219a126e144a1ded3a12ed1744e561e2ac16dc4f126eea31c' 
  AND token = 'WS6m7AEww4nSdlS36ZjA7uvalJ0LmutxZ9b90/TFif8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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