SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec64d08132970ef3d22bcdf1a9d6d44eee6c84ebebb2daad87f9ab377ffcbcfe' 
  AND token = 'jogiS3t3unshgzLfe2ZBZgX3ZiFZYkSwQamYSoQBnwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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