SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fe83b21207c910149a049a13fdfbfd6ab9b614bc352680137894c6df53b5cc1' 
  AND token = 'kFlCl/GB+snJvL30a8x5RgINrr/v++djS7LPIK4E7Ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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