SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '746ab9aaeb323c0214019123a0ab1d414a06cfcff772cf7818461eec30d36fca' 
  AND token = 'qKNKYsU3twR4Das084MnB6wAKduLUwiuEwXBTLC6Yd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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