SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63bccc5bb1e125d84955d2d27457072fccc09f56b82bbc7cfd9091869e49d70c' 
  AND token = 'ZScQrEg3HquDKl8RzTt3uQYU+YtPTQHNeNyJDY/PW6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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