SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9fc97596b2a6106ce00917fdc78fa8f8458d80636da8b505febcec0f1c6a66dd' 
  AND token = 'oU9WP9bFz73CR3+NxBZJda9r6pIzL5UtyU+ZIbYTNIo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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