SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b66a287b968439ebe7cd74f561e37a116d7a752dd79da091a7a82ec7b7f4e563' 
  AND token = '8A/YOMFONZqcRTUEc5P4f/iDvNVYjlqOGOIBBkrsNJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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