SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ac09c14f15891f6769f60e5e2f5a16f764348dbba885b396cb08e67423c453f' 
  AND token = 'apjMvNqu+RNv3GNdHtUU2FS/SMQd7cp/aZb8VSYJhJw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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