SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69c4f08127c2e1381dbd8f8ef894458268f5d1329bf457c054779d45da9341a9' 
  AND token = '4qYSJmQkX/p8OqlIUZQGql4BjS0VtRN2Xc9jR/J5F4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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