SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'b125cb547a25f98bc7d8b784c6c78200319dfb4c19939ff00c37b0494c1a13bc' 
  AND token = 'RnrFaB5w8t66Mk/VAWAt/eYLkSCOiP8kZfWPDhSa5wY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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