SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eac8f8ff566bcb0382ac751fd4cbdee7e338f2b8956790d8d27edd0701bb8114' 
  AND token = 'FJHjsJLp6AN1A+/vOi5kGVqr31pVTGGJ+yi0OOnY/zU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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