SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9491fb89d7901f5686c6268c86c895d0ace2c33bd306bb506ff804a2cd7111af' 
  AND token = 'C8koa/6TLhj4Q/vMsrzZdVFfBsLW4+93XJSwZpOa1pM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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