SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6100cbd8f007f66182c52ee3e72f5abef25df6e8d38fa5f9361bfd1292cbe817' 
  AND token = 'QC80rlY8SIq7wh+MJfxh4zD2TQgdNYh6TjKZVgnF03c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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