SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '036f91ada4f36a51cc232f3fb188d52d2674c3f1da572fc0c1b1ac956bd4102c' 
  AND token = 'MA3A8hh6GJCiVW9frFWuj85MbfQ6PsGMzK5MgK4pKCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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