SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '170e3a96e8447e367bf17c0249a337d70bc9c926b4072451720c803abc37f012' 
  AND token = 'HzoOvwCwxtPOFmQyNuufYLc2QzdxQToWv0g+g5rYZNY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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