SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6247493415347e9e89529bdb7718c453e5728812eb345d2ab342cd83197cdd44' 
  AND token = 'acS9j4gdQ7BXFqMOKyycoJv8PK+ChEfIeh+llmb+OZA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}