SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'aaf4fa28ba129f515e74286c6cf27fb24f60ad8304923113979c051c2b38d283' 
  AND token = '4Xm7ub8mZPjV6X+7FXMpvay57pNE6mFyBPnmPXHF9Kg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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