SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '167b8501284f905ee3d394e22f8d6ece22ec8c33b42398f7e1349a1a0f6c7100' 
  AND token = 'vNJeDekhe71mV69PjLTigYXtiCfcWIHbzwBlinB+JRU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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