SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd78afe7080a70929ccecb01b400285df5c81c2650365bc5ccb17731145822b87' 
  AND token = 'Vg2IfmfWejB4ljlFNDyTsiD0uAQ8MhEYjJDA3H7vddw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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