SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c08d2c893b931f96efcf0c8c2c10baf3d335381b572ae22210ab69cfefff167' 
  AND token = 'ZnSsPegYdSpQnND3CTVisBN/26N+WCO+2HW426iMrQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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