SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15efe194a231ba4b7e940b0ad1beff391179ea5c1d90bfc25ba2f85323be084c' 
  AND token = 'ptHoMF45WbBJmoj5LVw537WpoFLj2OcvDcdTJaXy58o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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