SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96a043add4f55089c0f28327579db0354f51a2ff180afc15d55ee6f1dc532e94' 
  AND token = 'fyPTs057J0z+4jfTC5ZlO2x/IF6/b9T3/2zd8nM1XiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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