SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '362d2ace64f809c5d20735afb794c13a27805e99336898a210aef759ade2f4a7' 
  AND token = 'BZYBhePJFDAV0wYJekAXvletDknDIp/WUdwwZZ5xv0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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