SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd466afdfdf87f5e825df2ac09583ee47d7a6040bc24f1618b38ee9a5d27efa1' 
  AND token = 'HkYnEfNgmpJUuJ/uOZJBPhYswKlKcoT5xT+jktFMWFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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