SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60b36ac45b70a99611fbc96fd89c2ed138597b9b62f44b0e01435dbd3c8de864' 
  AND token = 'gIBeXIZ9iBY97mqzpXLMGsvJBDBG5UqiWRwndBYL+oA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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