SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '212989dfa02f85775353866290b73692453f9339e12e0d0fe984476fb97d8bb8' 
  AND token = 'cxtodrMqzvEogBYX7Iw3R+YN34kihzYtCAexpe+++xY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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