SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef1bd322a19713b5d3215270ae694029b88b37f12ae6755cefb078492f8e06ad' 
  AND token = 'ZyQBHRVPeujgkg84sUTRw9ps0PAy2jubJJpnT4omCtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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