SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8798c229d251100c41ad8b2ca6f402b6d9dadf543c3cfd1a9da1946685f60d46' 
  AND token = '0GuDdpylWW8fZMlPTSNYz5C6SpuIxKuzsqBho1BKfWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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