SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f7a81602f193e62392af7ba843361cf554f74ea675ef0e5c021706ea08ad9fb' 
  AND token = 'zeR1IqkiwFVpfnYUoKQYuDpFj/+VAAh2diAxD7o22jQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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