SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db9c85c41082dbead8beeb9ab8434bf2ae95e98412572989644b8cf62851801e' 
  AND token = 'PmZIBjW2f9wT8fMWh/ffhLJ3KWxZLHqCUZkRqpZeA40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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