SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6804ed3d8c63b2db30b156c402ca4a19056e92172869a60e920025fe3ebe6165' 
  AND token = 'TQzLef5+vbeLU1L4i8pUEKdnDdAZ6uvw8KirKLqf6bY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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