SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1722289ec722ce689beb1758f490f77484eb39708e939f60cd240d29b92c55d' 
  AND token = 'lHMK3B/rbdYnkUKHytxtxPaCpOYgweaA9b1EwSThuew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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