SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f0e4dbb2e26c2687a26277723a20f95a6a4c1b7f88ed82244865376150e215d' 
  AND token = '8AflQ0KqSr+wCtjt0YDOckdhKiz0tdnYD7bxXxSFcT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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