SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '46acfc99a7d582d0340cb79d5a34fae747cbe80e2e9579d1820bde72f3a7e895' 
  AND token = 'GarcJb3nfbZr50b5MfSolzl0XQxMlG2M9py8/Hy9yGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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