SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6af13c44f966a10125abfac2d1d9242ca004f872630009e0be2f7792a99d1a58' 
  AND token = 'IlELyaEnQIrSnHz8uZTiOAC8ojWzTwSYQluXOXj2oDM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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