SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b266696222b43e611224e77e71f4857824def621c60ed5ce6bfd3c6ca334a48c' 
  AND token = 'Hvewc279C0GUdIN5o+AA98uMggZcAXugePc6hA/6TDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}