SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd2239167a79143de85cc9f8399d53eda8e0271160439fa3cf2d3dfa513d85c9' 
  AND token = 'WPfa3yvlrGtQT6MKr+7gYxnTcRwcurOHXjh8lA73DUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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