SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b3d79e8f5393c8b176ef00256afb4d79b2edf5930caaafda4ba564cafee105d' 
  AND token = 'ARAt/g+PjjAxTBPH/nQipl/uMd6dXkDn3FXtdFZNwS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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