SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '032b0a841dde5a0d9e667de83f73f25eb2acbaf3795737fd232b61a358004de9' 
  AND token = 'tkwIubxtptQQ9cOxaLaKddEFPUdoFlLtmsoLBABpIq4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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