SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fcbe5455e582eb4cdd6abcd3acef4b2e499030d982bf918d28af5975417ecc4' 
  AND token = 'sD9qBdHh1WIsAJpZkLZt5sW3tCLWfmdtAikvjYn7A6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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