SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25c52890054e79b595ef61ff08632f0abb112e723839c218420060b9f534d44e' 
  AND token = 'ahwwYdc5eyEI47r7+c1j1gaZB0jWmsljJG59rO94chI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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