SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a27b90e196a35c23b40a51231fb042bb76d23988e8bcb49139b8cf601c93c0e' 
  AND token = 'zqYDdtGjxYpT6ZOijbHZ1swtq+c3Ez8vjFap3MHsCB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}