SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85c8272fc7849a03b2bc256427a565279a059defcbec49adaea7d7d12076e39c' 
  AND token = 'MbPhUxcxezZZ2dnyxHgHJsdQdPjog256P2yY1UTiuNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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