SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f1e1cf16fb8049d5d5e0e90098355973cc5e894106d43eda43b12792beb9e20' 
  AND token = 'WhQmZ46OrX9MjxmzwDsWpf5E0k8PaMKBAybSRbij2a4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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