SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a9ce3fb78e5d70205f1ce03b6516148016b57b0ade448162bc84ee11f33b649' 
  AND token = 'c29L8fn3WDT3zRpK2neflD0vCFGaX5jzI1ZjjSfuxV4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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