SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4a5f2c91550ea5598dc350975209fa208a8e7ceb959317f7fe595dabd066fbfa' 
  AND token = 'L+Em3IxZOji5KtwM4bkf4aBJpMdyL0ckWPxTLaLX6+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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