SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd8a843d33c919872ac6e9525f7acc7f3531152c617f5fe91efebe2003b0a39fe' 
  AND token = '9pvA9+4Tm1Hr+NEY+odjwfYSgqRlMhQhgFnsIP/FvoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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