SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e5e1436ba1163965557962d9179edea83785661bbff6f5caa47f93597904e097' 
  AND token = 'MNiWpMvrFICHmjo9GPSWF3PdqQup4btpsT+1fvFVpjM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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