SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09d8c4a4c031698b77e5a2e99dda443d2618deeed30b8fd4266b50a79d855b3f' 
  AND token = 'OuFIrxWGo/0+3mDzXYtbl/l0vZm/JmjnmvIqVgw3x+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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