SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ffcc3cb5f07d33319aac8da6a6a9c9f29e59e894786155ec7c425d217439ba' 
  AND token = 'WuZTMLLGeq45KxTjXfEpF1+NAkq0FijWQEVXUFI23s0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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