SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8bd3abadb01ce23160f273ebffb77ca9bedf7c5069dc409525e6fcc4a406097' 
  AND token = 'Gu0zcfp/wSNKeSWn/DDAqL8YyY/NFhOUHgjYQYjHevo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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