SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bfe561ab54c4b96f2bf0ce2337488606909b2bce63c686dbfced9f877b5218f' 
  AND token = 'W6NGJ9hX/UI8BjzrjwwbEOdKKa2gcA+2D+08EuBlAbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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